diff --git a/CODEMAP.md b/CODEMAP.md
index 9b88938..2fee138 100644
--- a/CODEMAP.md
+++ b/CODEMAP.md
@@ -302,7 +302,7 @@ casse cette arithmetique *structurellement* — `BeginPlay` loggue une **Error**
 | `ProcessPendingChunks` | 301 | Drains ProcessQueue under per-frame budget; reads the per-request cancellation token before removing its map entry, drops obsolete/aborted results, then applies each live result via `ApplyTileResult`. |
 | `ApplyTileResult` | — | **Shared game-thread apply** for one `FChunkResult` (async drain + sync carve): discards stale generation epochs and keys no longer desired, marks loaded, ingests capture, EMPTY releases the tile's existing component (a re-gen can flip content→empty on band change — old geometry must not linger), else `ApplyMeshToTile`. Returns true iff a visible mesh uploaded (counts the budget). Doesn't touch `PendingTiles` (caller's). |
 | `FVoxelStackSampler` / `FScopedVoxelStackRegistration` (`VoxelStackSampler.h/.cpp`) | — | **Diagnostic stack-sampling profiler (2026-09-13), off by default.** A sampler thread captures registered generation workers' stacks (`CaptureThreadStackBackTrace`) every N µs and tags each with the tile's LOD. It symbolises after the run (inline frames too) into CSV plus a summary under `Saved/`. Registration is per tile TASK in `LoadTile` (and the export's tasks), never per sample; disabled costs one relaxed atomic load. Game `-voxel.SampleStacks=<us>`, commandlet `-samplestacks[=us]`. ~4-5% overhead at 1 ms, so trust large shares, not single-digit deltas. Report: `PERF-SAMPLED.md`. |
-| Room-cache performance (2026-09-13): `VF_FindPlayerFitPointForRoomMemoized` / `GPlayerFitMemo` (`VoxelCaveMorphology.cpp`), `voxel.TileCacheWindow` + `VoxelGenLOD::TileOriginVoxels/TileCellsPerAxis` (`VoxelGenerator.h`), `FChunkSDFSpatialIndex` | — | **Player-fit memo:** exact 97-word key, process-wide, `voxel.PlayerFitMemo`. **Tile cache window:** the room cache covers the requesting tile's footprint plus a fixed collect margin. It is set via `TGuardValue` in `GenerateMesh`/classify, and is window-invariant by construction (the margin does not grow with the tile). **Spatial index:** ordered XY buckets over cache primitives, exact rejection. The `static_assert` in `VoxelStrateTypes.h` ties `VF_STRATE_PARAM_FIELDS` to `FStrateGenerationParams` (83 fields + 8 B padding). |
+| Room-cache performance (2026-09-13): `VF_FindPlayerFitPointForRoomMemoized` / `GPlayerFitMemo` (`VoxelCaveMorphology.cpp`), `voxel.TileCacheWindow` + `VoxelGenLOD::TileOriginVoxels/TileCellsPerAxis` (`VoxelGenerator.h`), `FChunkSDFSpatialIndex` | — | **Player-fit memo:** exact 97-word key, process-wide, `voxel.PlayerFitMemo`. **Tile cache window:** the room cache covers the requesting tile's footprint plus a fixed collect margin. It is set via `TGuardValue` in `GenerateMesh`/classify, and is window-invariant by construction (the margin does not grow with the tile). **LOD-gated:** fused path at LOD ≥ `voxel.TileCacheWindowMinLOD` (3), op-stack at LOD ≥ `voxel.TileCacheWindowOpStackMinLOD` (4); lower LODs keep the 4-chunk worker window, because the tile window slowed LOD0 evaluation ~6%. Strates whose authored terrain ops exceed the proven 256-voxel extent (or are malformed/unloaded) fall back to the legacy window (`VF_ComputeTerrainOpEnvelope`). `voxel.SpatialIndex` is -1 auto (off at fused LOD0, on elsewhere), 0 or 1. **Spatial index:** ordered XY buckets over cache primitives, exact rejection. The `static_assert` in `VoxelStrateTypes.h` ties `VF_STRATE_PARAM_FIELDS` to `FStrateGenerationParams` (83 fields + 8 B padding). |
 | `GenerateTileResult` | — | **Shared worker-side gen** for one tile (async `LoadTile` task + sync `SyncRemeshTile`): [ClassifyTile (T1.d) + exact validation, only when `voxel.OuterClassifierMode=1`; **default 0 since 2026-09-13**] → `GenerateMesh`/`GenerateSheetMesh` → `BuildTileStreamSet`. Reads Generator/Mesher only → safe on a worker or the game thread; fills `FChunkResult`, no enqueue. |
 | `SyncRemeshTile` | — | **INSTANT DIG**: level-0 same-frame re-mesh on the game thread (`GenerateTileResult` + `ApplyTileResult` inline, Cells=CHUNK_SIZE/Step=1 + strate band, no capture). Used for the tile under the brush centre so a carve is visible THIS frame; one full-res gen on the game thread. |
 | `UpdateChunksAroundPosition` | 362 | Builds desired set, cancels pending keys that left it, sorts from the **true pawn position**, submits the occupied/support LOD0 tile and the next tile along the pawn heading as an absolute `BackgroundHigh` prefix, then loads/unloads and handles LOD changes. **Delta cull**: `BuildDesiredTiles` returns the LEAVERS (stamped `DesiredStamped` map, one sweep) — only those + `TransitionHold` are considered per crossing, not every loaded tile. `BuildDesiredTiles` also applies `RenderDistanceChunks`: the outermost shell widens to cover the distance — as level-MaxClipLevel MC tiles, or (F18 `bFarSheetRing`) as a SHEET ring at level MaxClipLevel+span (covered-check vs the MaxClipLevel box; `VF_OuterShell` shared with `IsTileInClipRange` so the cull sees the same horizon), dz pre-clamped to the vertical band. **§9.3 anchors:** also prunes dead `StreamingAnchors` + detects their chunk crossings → rebuilds the desired set when an anchor moves/(un)registers (`bAnchorsMoved`/`bForceDesiredRebuild`), same cadence as player movement. §8.10. |
diff --git a/Source/VoxelForge/Private/VoxelCaveMorphology.cpp b/Source/VoxelForge/Private/VoxelCaveMorphology.cpp
index 9c6193c..aa3f1f9 100644
--- a/Source/VoxelForge/Private/VoxelCaveMorphology.cpp
+++ b/Source/VoxelForge/Private/VoxelCaveMorphology.cpp
@@ -1538,12 +1538,13 @@ namespace
     template <typename FVisit>
     static int32 VF_ForEachSpatialCandidate(
         const FChunkSDFSpatialIndex& Index, int32 ItemCount,
-        float WorldX, float WorldY, FVisit&& Visit)
+        float WorldX, float WorldY, FVisit&& Visit,
+        bool bUseSpatialIndex = true)
     {
         int32 Begin = 0;
         int32 End = 0;
         int32 CandidateCount = 0;
-        if (Index.GetRange(WorldX, WorldY, Begin, End))
+        if (bUseSpatialIndex && Index.GetRange(WorldX, WorldY, Begin, End))
         {
             for (int32 Cursor = Begin; Cursor < End; ++Cursor)
             {
@@ -1786,6 +1787,10 @@ struct FBuildRoomMouthRise
 struct FVFRoomGraphReach
 {
     float DirectRoomReach = 0.0f;
+    // Complete XY reach of a room body plus any authored terrain operation that can be selected
+    // for that room. This is also used by the STORE cull; leaving it out would drop a room whose
+    // pit/chimney/detail override extends beyond the base SDF body.
+    float TerrainOpReach = 0.0f;
     float FloorReliefEnvelope = 0.0f;
     float BlendEnvelope = 0.0f;
     float MaxTunnelLength = 0.0f;
@@ -1808,8 +1813,324 @@ static float VF_RoomShapeReachUpperBound(float RadiusXY, float RadiusZ)
     return FMath::Max3(Ellipsoid, RoundedBox, Capsule);
 }
 
+// Terrain operations are authored outside FStrateGenerationParams and are selected per room at
+// cache-build time. The tile-window proof must therefore include both the transported params and
+// every operation that the pool can select. The limit is deliberately finite: an authored feature
+// beyond it uses the legacy worker window, while the fixed-margin proof remains valid for all
+// assets that stay inside this envelope.
+static constexpr float VF_MaxProvenTerrainOpExtent = 256.0f;
+
+static bool VF_ComputeTerrainOpEnvelope(
+    const FStrateGenerationParams& Params,
+    const TArray<FStrateTerrainOpEntry>* TerrainOps,
+    float BaseRoomReach,
+    float AllRoomRadiusEnvelope,
+    float BlendEnvelope,
+    float& OutReach)
+{
+    float MaxReach = BaseRoomReach;
+    float MaxAuthoredExtent = 0.0f;
+    bool bHasActiveTerrainOperation = false;
+
+    auto RecordAuthoredExtent = [&](float Extent) -> bool
+    {
+        if (!FMath::IsFinite(Extent) || Extent < 0.0f)
+        {
+            return false;
+        }
+        bHasActiveTerrainOperation = true;
+        MaxAuthoredExtent = FMath::Max(MaxAuthoredExtent, Extent);
+        return MaxAuthoredExtent <= VF_MaxProvenTerrainOpExtent;
+    };
+    auto RecordReach = [&](float Reach) -> bool
+    {
+        if (!FMath::IsFinite(Reach) || Reach < 0.0f)
+        {
+            return false;
+        }
+        MaxReach = FMath::Max(MaxReach, Reach);
+        return FMath::IsFinite(MaxReach);
+    };
+    auto RecordDetail = [&](float EffectRange) -> bool
+    {
+        return RecordAuthoredExtent(EffectRange)
+            && RecordReach(BaseRoomReach + EffectRange);
+    };
+    auto RecordStructural = [&](float EffectExtent, float FeatureReach) -> bool
+    {
+        return RecordAuthoredExtent(EffectExtent)
+            && RecordReach(FeatureReach);
+    };
+
+    auto AccumulateParams = [&](const FStrateGenerationParams& OpParams) -> bool
+    {
+        const float OperationValues[] = {
+            OpParams.TerraceStepHeight,
+            OpParams.TerraceHardness,
+            OpParams.TerraceNoiseDisplacement,
+            OpParams.LayerLineSpacing,
+            OpParams.LayerLineDepth,
+            OpParams.OverhangStrength,
+            OpParams.OverhangDepth,
+            OpParams.OverhangFrequency,
+            OpParams.RibbingSpacing,
+            OpParams.RibbingDepth,
+            OpParams.CliffStrength,
+            OpParams.ScallopStrength,
+            OpParams.ScallopFrequency,
+            OpParams.ArchDensity,
+            OpParams.ArchMinRadius,
+            OpParams.ArchMaxRadius,
+            OpParams.ColumnDensity,
+            OpParams.ColumnMinRadius,
+            OpParams.ColumnMaxRadius,
+            OpParams.PitDensity,
+            OpParams.PitMinRadius,
+            OpParams.PitMaxRadius,
+            OpParams.PitDepth,
+            OpParams.ChimneyDensity,
+            OpParams.ChimneyMinRadius,
+            OpParams.ChimneyMaxRadius,
+            OpParams.ChimneyHeight,
+            OpParams.DomeDensity,
+            OpParams.DomeMinRadius,
+            OpParams.DomeMaxRadius,
+            OpParams.DomeHeightRatio,
+            OpParams.PinchDensity,
+            OpParams.PinchStrength,
+            OpParams.PinchLength};
+        for (const float Value : OperationValues)
+        {
+            if (!FMath::IsFinite(Value))
+            {
+                return false;
+            }
+        }
+
+        if (OpParams.TerraceStepHeight > 0.0f)
+        {
+            if (OpParams.TerraceHardness < 0.0f || OpParams.TerraceHardness > 1.0f
+                || OpParams.TerraceNoiseDisplacement < 0.0f)
+            {
+                return false;
+            }
+            if (!RecordDetail(
+                    OpParams.TerraceStepHeight * 3.0f
+                    + OpParams.TerraceNoiseDisplacement + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.LayerLineSpacing > 0.0f)
+        {
+            if (OpParams.LayerLineDepth < 0.0f
+                || !RecordDetail(OpParams.LayerLineSpacing
+                    + OpParams.LayerLineDepth + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.RibbingSpacing > 0.0f)
+        {
+            if (OpParams.RibbingDepth < 0.0f
+                || !RecordDetail(OpParams.RibbingSpacing
+                    + OpParams.RibbingDepth + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.CliffStrength > 0.0f)
+        {
+            if (!RecordDetail(OpParams.CliffStrength + 8.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.ScallopStrength > 0.0f)
+        {
+            if (OpParams.ScallopFrequency <= 0.0f
+                || !RecordDetail(
+                    4.0f / OpParams.ScallopFrequency
+                    + OpParams.ScallopStrength + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.OverhangStrength > 0.0f)
+        {
+            if (OpParams.OverhangDepth < 0.0f
+                || OpParams.OverhangFrequency <= 0.0f
+                || !RecordDetail(OpParams.OverhangDepth * 2.0f + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.ArchDensity > 0.0f)
+        {
+            if (OpParams.ArchMinRadius < 0.0f || OpParams.ArchMaxRadius < 0.0f)
+            {
+                return false;
+            }
+            const float Radius = FMath::Max(OpParams.ArchMinRadius, OpParams.ArchMaxRadius);
+            if (!RecordStructural(
+                    Radius + 4.0f,
+                    AllRoomRadiusEnvelope * 1.2f + Radius + BlendEnvelope * 3.0f + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.ColumnDensity > 0.0f)
+        {
+            if (OpParams.ColumnMinRadius < 0.0f || OpParams.ColumnMaxRadius < 0.0f)
+            {
+                return false;
+            }
+            const float Radius = FMath::Max(OpParams.ColumnMinRadius, OpParams.ColumnMaxRadius);
+            if (!RecordStructural(
+                    Radius + 6.0f,
+                    AllRoomRadiusEnvelope * 0.75f + Radius + 6.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.PitDensity > 0.0f)
+        {
+            if (OpParams.PitMinRadius < 0.0f || OpParams.PitMaxRadius < 0.0f
+                || OpParams.PitDepth < 0.0f)
+            {
+                return false;
+            }
+            const float Radius = FMath::Max(OpParams.PitMinRadius, OpParams.PitMaxRadius);
+            if (!RecordStructural(
+                    2.0f * Radius + OpParams.PitDepth + BlendEnvelope + 4.0f,
+                    AllRoomRadiusEnvelope * 0.6f + 2.0f * Radius
+                        + OpParams.PitDepth + BlendEnvelope + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.ChimneyDensity > 0.0f)
+        {
+            if (OpParams.ChimneyMinRadius < 0.0f || OpParams.ChimneyMaxRadius < 0.0f
+                || OpParams.ChimneyHeight < 0.0f)
+            {
+                return false;
+            }
+            const float Radius = FMath::Max(
+                OpParams.ChimneyMinRadius, OpParams.ChimneyMaxRadius);
+            if (!RecordStructural(
+                    2.0f * Radius + OpParams.ChimneyHeight + BlendEnvelope + 4.0f,
+                    AllRoomRadiusEnvelope * 0.6f + 2.0f * Radius
+                        + OpParams.ChimneyHeight + BlendEnvelope + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.DomeDensity > 0.0f)
+        {
+            if (OpParams.DomeMinRadius < 0.0f || OpParams.DomeMaxRadius < 0.0f
+                || OpParams.DomeHeightRatio < 0.0f)
+            {
+                return false;
+            }
+            const float Radius = FMath::Max(OpParams.DomeMinRadius, OpParams.DomeMaxRadius);
+            if (!RecordStructural(
+                    Radius * (1.0f + OpParams.DomeHeightRatio) + 4.0f,
+                    AllRoomRadiusEnvelope * 0.4f + Radius
+                        * (1.0f + OpParams.DomeHeightRatio) + 4.0f))
+            {
+                return false;
+            }
+        }
+        if (OpParams.PinchDensity > 0.0f)
+        {
+            if (OpParams.PinchStrength < 0.0f || OpParams.PinchLength < 0.0f)
+            {
+                return false;
+            }
+            const float Extent = FMath::Max(OpParams.PinchStrength, OpParams.PinchLength);
+            if (!RecordStructural(
+                    Extent + 5.0f,
+                    AllRoomRadiusEnvelope * 0.85f + Extent + 5.0f))
+            {
+                return false;
+            }
+        }
+        return true;
+    };
+
+    if (!AccumulateParams(Params))
+    {
+        return false;
+    }
+
+    if (TerrainOps != nullptr)
+    {
+        for (const FStrateTerrainOpEntry& Entry : *TerrainOps)
+        {
+            if (!FMath::IsFinite(Entry.Probability)
+                || Entry.Probability < 0.0f || Entry.Probability > 1.0f
+                || !FMath::IsFinite(Entry.Weight)
+                || Entry.Weight < 0.0f || Entry.Weight > 3.0f)
+            {
+                return false;
+            }
+            if (Entry.Probability <= 0.0f || Entry.Weight <= 0.0f)
+            {
+                continue;
+            }
+            if (Entry.Operation.IsNull())
+            {
+                continue;
+            }
+            const UVoxelTerrainOpDefinition* Operation = Entry.Operation.Get();
+            if (Operation == nullptr)
+            {
+                // A referenced but unloaded asset is not a proof of absence. Keep the legacy
+                // window until the manager has a concrete definition to inspect.
+                return false;
+            }
+            switch (Operation->Type)
+            {
+            case EVoxelTerrainOpType::Terrace:
+            case EVoxelTerrainOpType::LayerLines:
+            case EVoxelTerrainOpType::Ribbing:
+            case EVoxelTerrainOpType::Cliff:
+            case EVoxelTerrainOpType::Scallop:
+            case EVoxelTerrainOpType::Overhang:
+            case EVoxelTerrainOpType::Arch:
+            case EVoxelTerrainOpType::Column:
+            case EVoxelTerrainOpType::Pit:
+            case EVoxelTerrainOpType::Chimney:
+            case EVoxelTerrainOpType::Dome:
+            case EVoxelTerrainOpType::Pinch:
+                break;
+            default:
+                return false;
+            }
+
+            FStrateGenerationParams OperationParams{};
+            Operation->ApplyTo(OperationParams, Entry.Weight);
+            if (!AccumulateParams(OperationParams))
+            {
+                return false;
+            }
+        }
+    }
+
+    // Keep the field at zero when the strate has no active terrain operation.  The caller already
+    // has the base room envelope; using that same value as a second global room radius would make
+    // the legacy/no-op path store extra rooms and could change the canonical field.  Active pools
+    // publish the wider envelope so the tile proof and STORE cull see pits/chimneys/detail reach.
+    OutReach = bHasActiveTerrainOperation ? MaxReach : 0.0f;
+    return FMath::IsFinite(OutReach)
+        && FMath::IsFinite(MaxAuthoredExtent)
+        && MaxAuthoredExtent <= VF_MaxProvenTerrainOpExtent;
+}
+
 static bool VF_ComputeRoomGraphReach(
     const FStrateGenerationParams& Params,
+    const TArray<FStrateTerrainOpEntry>* TerrainOps,
     FVFRoomGraphReach& OutReach)
 {
     const float RelevantParams[] = {
@@ -1892,9 +2213,17 @@ static bool VF_ComputeRoomGraphReach(
             FMath::Abs(Params.TunnelMaxRadius)) * 1.18f);
     const float MaxTunnelLength = FMath::Max(
         Params.MaxTunnelLength, 0.0f);
-    const float DirectRoomReach = VF_RoomShapeReachUpperBound(
+    const float BaseDirectRoomReach = VF_RoomShapeReachUpperBound(
         AllRoomRadiusEnvelope, AllRoomHeightEnvelope)
         + FloorReliefEnvelope + BlendEnvelope * 3.0f;
+    float TerrainOpReach = BaseDirectRoomReach;
+    if (!VF_ComputeTerrainOpEnvelope(
+            Params, TerrainOps, BaseDirectRoomReach,
+            AllRoomRadiusEnvelope, BlendEnvelope, TerrainOpReach))
+    {
+        return false;
+    }
+    const float DirectRoomReach = FMath::Max(BaseDirectRoomReach, TerrainOpReach);
     const float TunnelInfluence = FMath::Abs(Params.TunnelWarpStrength)
         + TunnelRadiusEnvelope + BlendEnvelope * 3.0f;
     const float MaxInfluence = FMath::Max(DirectRoomReach, TunnelInfluence);
@@ -1958,6 +2287,7 @@ static bool VF_ComputeRoomGraphReach(
     }
 
     OutReach.DirectRoomReach = DirectRoomReach;
+    OutReach.TerrainOpReach = TerrainOpReach;
     OutReach.FloorReliefEnvelope = FloorReliefEnvelope;
     OutReach.BlendEnvelope = BlendEnvelope;
     OutReach.MaxTunnelLength = MaxTunnelLength;
@@ -2000,9 +2330,10 @@ static bool VF_MayHaveRoomGraphFeature(
         {
             return true;
         }
-        const float RoomReach = VF_RoomShapeReachUpperBound(
+        const float BaseRoomReach = VF_RoomShapeReachUpperBound(
             Room.RadiusXY, Room.RadiusZ)
             + Reach.FloorReliefEnvelope + Reach.BlendEnvelope * 3.0f;
+        const float RoomReach = FMath::Max(BaseRoomReach, Reach.TerrainOpReach);
         if (!FMath::IsFinite(RoomReach) || RoomReach < 0.0f)
         {
             return true;
@@ -5474,7 +5805,8 @@ bool VoxelCaveMorphology::MayHaveFeatureInSearchBox(
     float SearchMaxX, float SearchMaxY,
     const FStrateGenerationParams& Params,
     uint32 Seed, int32 StrateIndex,
-    bool bUseZ, float SearchMinZ, float SearchMaxZ)
+    bool bUseZ, float SearchMinZ, float SearchMaxZ,
+    const TArray<FStrateTerrainOpEntry>* TerrainOps)
 {
     if (!FMath::IsFinite(SearchMinX) || !FMath::IsFinite(SearchMinY)
         || !FMath::IsFinite(SearchMaxX) || !FMath::IsFinite(SearchMaxY)
@@ -5496,7 +5828,7 @@ bool VoxelCaveMorphology::MayHaveFeatureInSearchBox(
     }
 
     FVFRoomGraphReach Reach;
-    if (!VF_ComputeRoomGraphReach(Params, Reach))
+    if (!VF_ComputeRoomGraphReach(Params, TerrainOps, Reach))
     {
         return true;
     }
@@ -5639,10 +5971,11 @@ bool VoxelCaveMorphology::MayHaveFeatureInSearchBox(
 }
 
 bool VoxelCaveMorphology::IsRoomGraphWindowInvariant(
-    const FStrateGenerationParams& Params)
+    const FStrateGenerationParams& Params,
+    const TArray<FStrateTerrainOpEntry>* TerrainOps)
 {
     FVFRoomGraphReach Reach;
-    return VF_ComputeRoomGraphReach(Params, Reach);
+    return VF_ComputeRoomGraphReach(Params, TerrainOps, Reach);
 }
 
 //=============================================================================
@@ -5707,7 +6040,8 @@ void VoxelCaveMorphology::BuildChunkCache(
     // behavior below.  The tile-window optimization is only a field-preserving optimization for
     // the finite parameter envelope accepted by VF_ComputeRoomGraphReach.
     FVFRoomGraphReach FeatureReach;
-    const bool bHasFeatureReach = VF_ComputeRoomGraphReach(Params, FeatureReach);
+    const bool bHasFeatureReach = VF_ComputeRoomGraphReach(
+        Params, TerrainOps, FeatureReach);
 
     //=========================================================================
     // INFLUENCE RADII
@@ -5801,7 +6135,9 @@ void VoxelCaveMorphology::BuildChunkCache(
     auto RoomReachesSearchBox = [&](const FVector& C, float RadiusXY, float RadiusZ) -> bool
     {
         const float ShapeReach = VF_RoomShapeReachUpperBound(RadiusXY, RadiusZ);
-        const float Reach = ShapeReach + FloorReliefEnvelope + BlendEnvelope * 3.0f;
+        const float Reach = FMath::Max(
+            ShapeReach + FloorReliefEnvelope + BlendEnvelope * 3.0f,
+            bHasFeatureReach ? FeatureReach.TerrainOpReach : 0.0f);
         const float dx = FMath::Max3((float)(SearchMinX - C.X), 0.0f, (float)(C.X - SearchMaxX));
         const float dy = FMath::Max3((float)(SearchMinY - C.Y), 0.0f, (float)(C.Y - SearchMaxY));
         return (dx * dx + dy * dy) <= Reach * Reach;
@@ -6766,6 +7102,10 @@ void VoxelCaveMorphology::BuildChunkCache(
                     FMath::Abs(CR.ShapeA.Z));
             }
             MaxExtent = ShapeReach + FloorReliefEnvelope + BlendEnvelope * 3.0f;
+            if (bHasFeatureReach)
+            {
+                MaxExtent = FMath::Max(MaxExtent, FeatureReach.TerrainOpReach);
+            }
             CR.CullRadiusSq = MaxExtent * MaxExtent;
         }
 
@@ -7004,7 +7344,8 @@ float VoxelCaveMorphology::EvaluateSDFCached(
     float WorldX, float WorldY, float WorldZ,
     const FChunkSDFCache& Cache,
     float SDFBlendRadius,
-    int32* OutNearestRoomIdx)
+    int32* OutNearestRoomIdx,
+    bool bUseSpatialIndex)
 {
     VoxelDensityProfile::FScopedTimer ProfileTimer(
         VoxelDensityProfile::EBucket::RoomGraphSdf);
@@ -7117,7 +7458,8 @@ float VoxelCaveMorphology::EvaluateSDFCached(
     };
 
     const int32 RoomCandidateCount = VF_ForEachSpatialCandidate(
-        Cache.RoomSpatialIndex, Cache.Rooms.Num(), WorldX, WorldY, EvaluateRoom);
+        Cache.RoomSpatialIndex, Cache.Rooms.Num(), WorldX, WorldY, EvaluateRoom,
+        bUseSpatialIndex);
     if (VoxelDensityProfile::AreCountersEnabled())
     {
         VoxelDensityProfile::AddCounter(
@@ -7148,7 +7490,7 @@ float VoxelCaveMorphology::EvaluateSDFCached(
     };
     VF_ForEachSpatialCandidate(
         Cache.RoomFloorJoinSpatialIndex, Cache.RoomFloorJoins.Num(),
-        WorldX, WorldY, EvaluateJoin);
+        WorldX, WorldY, EvaluateJoin, bUseSpatialIndex);
 
     //=========================================================================
     // Tunnel SDFs
@@ -7188,7 +7530,8 @@ float VoxelCaveMorphology::EvaluateSDFCached(
     };
 
     const int32 TunnelCandidateCount = VF_ForEachSpatialCandidate(
-        Cache.TunnelSpatialIndex, Cache.Tunnels.Num(), WorldX, WorldY, EvaluateTunnel);
+        Cache.TunnelSpatialIndex, Cache.Tunnels.Num(), WorldX, WorldY, EvaluateTunnel,
+        bUseSpatialIndex);
     if (VoxelDensityProfile::AreCountersEnabled())
     {
         VoxelDensityProfile::AddCounter(
@@ -7207,7 +7550,8 @@ float VoxelCaveMorphology::EvaluateSDFCached(
 
 float VoxelCaveMorphology::EvaluateTunnelCoreSDF(
     float WorldX, float WorldY, float WorldZ,
-    const FChunkSDFCache& Cache)
+    const FChunkSDFCache& Cache,
+    bool bUseSpatialIndex)
 {
     const FVector Pos(WorldX, WorldY, WorldZ);
     float MinSDF = FLT_MAX;
@@ -7237,7 +7581,8 @@ float VoxelCaveMorphology::EvaluateTunnelCoreSDF(
     };
 
     VF_ForEachSpatialCandidate(
-        Cache.TunnelSpatialIndex, Cache.Tunnels.Num(), WorldX, WorldY, EvaluateTunnel);
+        Cache.TunnelSpatialIndex, Cache.Tunnels.Num(), WorldX, WorldY, EvaluateTunnel,
+        bUseSpatialIndex);
 
     return MinSDF;
 }
@@ -7245,7 +7590,8 @@ float VoxelCaveMorphology::EvaluateTunnelCoreSDF(
 FTunnelCoreWorldEvaluation VoxelCaveMorphology::EvaluateTunnelCoreWorld(
     float WorldX, float WorldY, float WorldZ,
     const FChunkSDFCache& Cache,
-    const FTunnelSupportFloorColumn* SupportColumn)
+    const FTunnelSupportFloorColumn* SupportColumn,
+    bool bUseSpatialIndex)
 {
     VoxelDensityProfile::FScopedTimer ProfileTimer(
         VoxelDensityProfile::EBucket::TunnelCoreWorld);
@@ -7358,7 +7704,8 @@ FTunnelCoreWorldEvaluation VoxelCaveMorphology::EvaluateTunnelCoreWorld(
     };
 
     const int32 TunnelCandidateCount = VF_ForEachSpatialCandidate(
-        Cache.TunnelSpatialIndex, Cache.Tunnels.Num(), WorldX, WorldY, EvaluateTunnel);
+        Cache.TunnelSpatialIndex, Cache.Tunnels.Num(), WorldX, WorldY, EvaluateTunnel,
+        bUseSpatialIndex);
     if (VoxelDensityProfile::AreCountersEnabled())
     {
         VoxelDensityProfile::AddCounter(
@@ -7371,14 +7718,17 @@ FTunnelCoreWorldEvaluation VoxelCaveMorphology::EvaluateTunnelCoreWorld(
 
 float VoxelCaveMorphology::EvaluateTunnelCoreWorldSDF(
     float WorldX, float WorldY, float WorldZ,
-    const FChunkSDFCache& Cache)
+    const FChunkSDFCache& Cache,
+    bool bUseSpatialIndex)
 {
-    return EvaluateTunnelCoreWorld(WorldX, WorldY, WorldZ, Cache).SDF;
+    return EvaluateTunnelCoreWorld(
+        WorldX, WorldY, WorldZ, Cache, nullptr, bUseSpatialIndex).SDF;
 }
 
 bool VoxelCaveMorphology::IsTunnelSupportFloorWorldPoint(
     float WorldX, float WorldY, float WorldZ,
-    const FChunkSDFCache& Cache)
+    const FChunkSDFCache& Cache,
+    bool bUseSpatialIndex)
 {
     const FVector Pos(WorldX, WorldY, WorldZ);
 
@@ -7462,7 +7812,7 @@ bool VoxelCaveMorphology::IsTunnelSupportFloorWorldPoint(
 
     int32 Begin = 0;
     int32 End = 0;
-    if (Cache.TunnelSpatialIndex.GetRange(WorldX, WorldY, Begin, End))
+    if (bUseSpatialIndex && Cache.TunnelSpatialIndex.GetRange(WorldX, WorldY, Begin, End))
     {
         TestRange(Begin, End);
     }
@@ -7494,7 +7844,8 @@ bool VoxelCaveMorphology::IsTunnelSupportFloorWorldPoint(
 void VoxelCaveMorphology::BuildTunnelSupportFloorColumn(
     float WorldX, float WorldY,
     const FChunkSDFCache& Cache,
-    FTunnelSupportFloorColumn& OutColumn)
+    FTunnelSupportFloorColumn& OutColumn,
+    bool bUseSpatialIndex)
 {
     VoxelDensityProfile::FScopedTimer ProfileTimer(
         VoxelDensityProfile::EBucket::TunnelCoreSupport);
@@ -7552,7 +7903,8 @@ void VoxelCaveMorphology::BuildTunnelSupportFloorColumn(
         }
     };
     const int32 CandidateCount = VF_ForEachSpatialCandidate(
-        Cache.TunnelSpatialIndex, Cache.Tunnels.Num(), WorldX, WorldY, EvaluateTunnel);
+        Cache.TunnelSpatialIndex, Cache.Tunnels.Num(), WorldX, WorldY, EvaluateTunnel,
+        bUseSpatialIndex);
     if (VoxelDensityProfile::AreCountersEnabled())
     {
         VoxelDensityProfile::AddCounter(
diff --git a/Source/VoxelForge/Private/VoxelDensityOpStack.cpp b/Source/VoxelForge/Private/VoxelDensityOpStack.cpp
index 1859010..983d33a 100644
--- a/Source/VoxelForge/Private/VoxelDensityOpStack.cpp
+++ b/Source/VoxelForge/Private/VoxelDensityOpStack.cpp
@@ -3822,6 +3822,21 @@ namespace
              *  voxel PRÈS D'UNE SURFACE, pas partout) sans que onze opérateurs la refassent chacun. */
             FStrateGenerationParams LocalParams;
             bool bLocalParamsValid = false;
+
+            // Window invariance is a cache-policy proof, not a sample evaluator.  Keep its result
+            // beside the worker-local source state so LOD0 does not pay the full reach walk once
+            // per voxel.
+            bool bTileCachePolicyValid = false;
+            bool bTileCachePolicyResult = false;
+            bool bTileCachePolicyHasContext = false;
+            int32 TileCachePolicySampleStep = 0;
+            FIntVector TileCachePolicyOrigin = FIntVector::ZeroValue;
+            int32 TileCachePolicyStep = 0;
+            int32 TileCachePolicyCells = 0;
+            uint32 TileCachePolicyFingerprint = 0xFFFFFFFFu;
+            uint32 TileCachePolicyLayout = 0xFFFFFFFFu;
+            uint64 TileCachePolicyManagerLifetimeId = 0;
+            const TArray<FStrateTerrainOpEntry>* TileCachePolicyTerrainOps = nullptr;
         };
 
         FState& State() const
@@ -3861,7 +3876,8 @@ namespace
             FTunnelSupportFloorColumn& OutColumn) const
         {
             VoxelCaveMorphology::BuildTunnelSupportFloorColumn(
-                WorldX, WorldY, Cache, OutColumn);
+                WorldX, WorldY, Cache, OutColumn,
+                VoxelGenLOD::ShouldUseSpatialIndex(false));
         }
 
         const FTunnelSupportFloorColumn* GetSupportColumn(const FVector& Position) const
@@ -3917,7 +3933,8 @@ namespace
                 const FVector& Position = S.LastWorldPosition;
                 const FTunnelSupportFloorColumn* SupportColumn = GetSupportColumn(Position);
                 S.LastTunnelCoreWorldEvaluation = VoxelCaveMorphology::EvaluateTunnelCoreWorld(
-                    Position.X, Position.Y, Position.Z, GetCache(), SupportColumn);
+                    Position.X, Position.Y, Position.Z, GetCache(), SupportColumn,
+                    VoxelGenLOD::ShouldUseSpatialIndex(false));
                 S.LastTunnelCoreEvaluationPosition = Position;
                 S.bLastTunnelCoreWorldEvaluationValid = true;
             }
@@ -3991,7 +4008,9 @@ namespace
          */
         float ProbeSdfUnwarped(float X, float Y, float Z) const
         {
-            return VoxelCaveMorphology::EvaluateSDFCached(X, Y, Z, GetCache(), P.SDFBlendRadius);
+            return VoxelCaveMorphology::EvaluateSDFCached(
+                X, Y, Z, GetCache(), P.SDFBlendRadius, nullptr,
+                VoxelGenLOD::ShouldUseSpatialIndex(false));
         }
 
         /** Le Z « effectif » : `VerticalScale` étire le monde AVANT le bruit. Pure fonction de Z et
@@ -4126,10 +4145,47 @@ namespace
             FIntVector RequestedTileOrigin = FIntVector::ZeroValue;
             int32 RequestedTileStep = SampleStep;
             int32 RequestedTileCells = 0;
-            const bool bUseTileCacheWindow = VoxelGenLOD::IsTileCacheWindowEnabled()
-                && VoxelGenLOD::GetThreadTileCacheWindow(
-                    RequestedTileOrigin, RequestedTileStep, RequestedTileCells)
-                && VoxelCaveMorphology::IsRoomGraphWindowInvariant(P);
+            const TArray<FStrateTerrainOpEntry>* TerrainOps = nullptr;
+            if (LiveManager)
+            {
+                const int32 ChunkX = FMath::FloorToInt(WorldX / (float)CHUNK_SIZE);
+                const int32 ChunkY = FMath::FloorToInt(WorldY / (float)CHUNK_SIZE);
+                const int32 ChunkZ = FMath::FloorToInt(WorldZ / (float)CHUNK_SIZE);
+                UVoxelStrateDefinition* Def = LiveManager->GetStrateForChunk(
+                    FIntVector(ChunkX, ChunkY, ChunkZ));
+                if (Def) { TerrainOps = &Def->TerrainOperations; }
+            }
+            const bool bTileWindowEligible = VoxelGenLOD::IsTileCacheWindowEnabled(false);
+            const bool bHasTileWindowContext = VoxelGenLOD::GetThreadTileCacheWindow(
+                RequestedTileOrigin, RequestedTileStep, RequestedTileCells);
+            const bool bTilePolicyKeyChanged =
+                !S.bTileCachePolicyValid
+                || S.bTileCachePolicyHasContext
+                    != (bTileWindowEligible && bHasTileWindowContext)
+                || S.TileCachePolicySampleStep != RequestedTileStep
+                || S.TileCachePolicyOrigin != RequestedTileOrigin
+                || S.TileCachePolicyStep != RequestedTileStep
+                || S.TileCachePolicyCells != RequestedTileCells
+                || S.TileCachePolicyFingerprint != ParamsFingerprint
+                || S.TileCachePolicyLayout != LayoutVersion
+                || S.TileCachePolicyManagerLifetimeId != ManagerLifetimeId
+                || S.TileCachePolicyTerrainOps != TerrainOps;
+            if (bTilePolicyKeyChanged)
+            {
+                S.bTileCachePolicyValid = true;
+                S.bTileCachePolicyHasContext = bTileWindowEligible && bHasTileWindowContext;
+                S.TileCachePolicySampleStep = RequestedTileStep;
+                S.TileCachePolicyOrigin = RequestedTileOrigin;
+                S.TileCachePolicyStep = RequestedTileStep;
+                S.TileCachePolicyCells = RequestedTileCells;
+                S.TileCachePolicyFingerprint = ParamsFingerprint;
+                S.TileCachePolicyLayout = LayoutVersion;
+                S.TileCachePolicyManagerLifetimeId = ManagerLifetimeId;
+                S.TileCachePolicyTerrainOps = TerrainOps;
+                S.bTileCachePolicyResult = S.bTileCachePolicyHasContext
+                    && VoxelCaveMorphology::IsRoomGraphWindowInvariant(P, TerrainOps);
+            }
+            const bool bUseTileCacheWindow = S.bTileCachePolicyResult;
             int32 RegionSize = 0;
             int32 RegionMinX = 0;
             int32 RegionMinY = 0;
@@ -4143,9 +4199,11 @@ namespace
             }
             else
             {
-                const int32 RegionChunks = SampleStep <= 1
-                    ? 1
-                    : (SampleStep >= 32 ? 4 : FMath::Max(4, (SampleStep + 3) / 4));
+                // Fine requests retain the historical four-chunk worker window. The op-stack
+                // tile-sized window is gated to LOD4+ (the fused path starts at LOD3), so
+                // LOD0-LOD2 and the op-stack's LOD3 floor do not pay a full tile rebuild on their
+                // critical path while still reusing neighbouring chunks on the same worker.
+                const int32 RegionChunks = 4;
                 RegionSize = CHUNK_SIZE * RegionChunks;
                 const int32 RegionCellX = FMath::FloorToInt(WorldX / (float)RegionSize);
                 const int32 RegionCellY = FMath::FloorToInt(WorldY / (float)RegionSize);
@@ -4157,17 +4215,6 @@ namespace
                 + (bUseTileCacheWindow ? static_cast<float>(SampleStep) : 0.0f)
                 + 2.0f;
 
-            const TArray<FStrateTerrainOpEntry>* TerrainOps = nullptr;
-            if (LiveManager)
-            {
-                const int32 ChunkX = FMath::FloorToInt(WorldX / (float)CHUNK_SIZE);
-                const int32 ChunkY = FMath::FloorToInt(WorldY / (float)CHUNK_SIZE);
-                const int32 ChunkZ = FMath::FloorToInt(WorldZ / (float)CHUNK_SIZE);
-                UVoxelStrateDefinition* Def = LiveManager->GetStrateForChunk(
-                    FIntVector(ChunkX, ChunkY, ChunkZ));
-                if (Def) { TerrainOps = &Def->TerrainOperations; }
-            }
-
             const FChunkSDFCache* PreviousActiveCache = S.ActiveCache;
             bool bRebuiltLocalCache = false;
             if (SampleStep > 1)
@@ -4247,9 +4294,10 @@ namespace
                 S.SupportColumns.Invalidate();
             }
 
+            const bool bUseSpatialIndex = VoxelGenLOD::ShouldUseSpatialIndex(false);
             float CaveSDF = VoxelCaveMorphology::EvaluateSDFCached(
                 WarpedX, WarpedY, WarpedZ, GetCache(), P.SDFBlendRadius,
-                &S.NearestRoom);
+                &S.NearestRoom, bUseSpatialIndex);
 
             //---------------------------------------------------------------
             // PITS & CHEMINÉES — coordonnées RÉELLES, SmoothMin dans le même canal SDF
@@ -4289,7 +4337,7 @@ namespace
             };
             VF_ForEachChunkSDFSpatialCandidate(
                 GetCache().PitSpatialIndex, GetCache().Pits.Num(),
-                WorldX, WorldY, EvaluatePit);
+                WorldX, WorldY, EvaluatePit, bUseSpatialIndex);
 
             auto EvaluateChimney = [&](int32 ChimneyIndex)
             {
@@ -4320,7 +4368,7 @@ namespace
             };
             VF_ForEachChunkSDFSpatialCandidate(
                 GetCache().ChimneySpatialIndex, GetCache().Chimneys.Num(),
-                WorldX, WorldY, EvaluateChimney);
+                WorldX, WorldY, EvaluateChimney, bUseSpatialIndex);
 
             InOut.Sdf = CaveSDF;
 
@@ -4332,7 +4380,8 @@ namespace
             const FTunnelSupportFloorColumn* SupportColumn = GetSupportColumn(
                 S.LastWorldPosition);
             S.LastTunnelCoreWorldEvaluation = VoxelCaveMorphology::EvaluateTunnelCoreWorld(
-                WorldX, WorldY, WorldZ, GetCache(), SupportColumn);
+                WorldX, WorldY, WorldZ, GetCache(), SupportColumn,
+                bUseSpatialIndex);
             S.LastTunnelCoreEvaluationPosition = S.LastWorldPosition;
             S.bLastTunnelCoreWorldEvaluationValid = true;
             if (S.LastTunnelCoreWorldEvaluation.bSupportFloor
@@ -4782,13 +4831,49 @@ namespace
                 return;
             }
 
+            int32 StrateIdx = 0;
+            const TArray<FStrateTerrainOpEntry>* TerrainOps = nullptr;
+            if (LiveManager)
+            {
+                StrateIdx = LiveManager->GetStrateIndex(
+                    ((float)CZ0 + 0.5f) * CHUNK_SIZE * VOXEL_SIZE);
+                for (int32 CZ = CZ0 + 1; CZ <= CZ1; ++CZ)
+                {
+                    if (LiveManager->GetStrateIndex(
+                            ((float)CZ + 0.5f) * CHUNK_SIZE * VOXEL_SIZE) != StrateIdx)
+                    {
+                        Unknown();
+                        return;
+                    }
+                }
+
+                // A room operation is part of the graph cache. Every Z slice covered by this
+                // proof must resolve to the same definition before one cache can represent it.
+                UVoxelStrateDefinition* Def0 = nullptr;
+                for (int32 CZ = CZ0; CZ <= CZ1; ++CZ)
+                {
+                    UVoxelStrateDefinition* Def =
+                        LiveManager->GetStrateForChunk(FIntVector(0, 0, CZ));
+                    if (CZ == CZ0)
+                    {
+                        Def0 = Def;
+                    }
+                    else if (Def != Def0)
+                    {
+                        Unknown();
+                        return;
+                    }
+                }
+                if (Def0) { TerrainOps = &Def0->TerrainOperations; }
+            }
+
             FIntVector RequestedTileOrigin = FIntVector::ZeroValue;
             int32 RequestedTileStep = FMath::Max(Ctx.Step, 1);
             int32 RequestedTileCells = 0;
-            const bool bUseTileCacheWindow = VoxelGenLOD::IsTileCacheWindowEnabled()
+            const bool bUseTileCacheWindow = VoxelGenLOD::IsTileCacheWindowEnabled(false)
                 && VoxelGenLOD::GetThreadTileCacheWindow(
                     RequestedTileOrigin, RequestedTileStep, RequestedTileCells)
-                && VoxelCaveMorphology::IsRoomGraphWindowInvariant(P);
+                && VoxelCaveMorphology::IsRoomGraphWindowInvariant(P, TerrainOps);
             const float RequestedTileExtent = static_cast<float>(
                 static_cast<int64>(RequestedTileStep)
                 * static_cast<int64>(RequestedTileCells));
@@ -4849,46 +4934,6 @@ namespace
                 return;
             }
 
-            int32 StrateIdx = 0;
-            const TArray<FStrateTerrainOpEntry>* TerrainOps = nullptr;
-            if (LiveManager)
-            {
-                StrateIdx = LiveManager->GetStrateIndex(
-                    ((float)CZ0 + 0.5f) * CHUNK_SIZE * VOXEL_SIZE);
-                for (int32 CZ = CZ0 + 1; CZ <= CZ1; ++CZ)
-                {
-                    if (LiveManager->GetStrateIndex(
-                            ((float)CZ + 0.5f) * CHUNK_SIZE * VOXEL_SIZE) != StrateIdx)
-                    {
-                        Unknown();
-                        return;
-                    }
-                }
-
-                // The room-op pool is part of the SDF: BuildChunkCache bakes pits, chimneys, and
-                // columns from it. Every chunk touched by this query must therefore resolve to the
-                // same definition before one cache can represent the box.
-                // GetStrateForChunk is a Z-layout lookup; the manager ignores
-                // X/Y. Check one representative per touched Z instead of
-                // repeating the same layout search for every coarse XY key.
-                UVoxelStrateDefinition* Def0 = nullptr;
-                for (int32 CZ = CZ0; CZ <= CZ1; ++CZ)
-                {
-                    UVoxelStrateDefinition* Def =
-                        LiveManager->GetStrateForChunk(FIntVector(0, 0, CZ));
-                    if (CZ == CZ0)
-                    {
-                        Def0 = Def;
-                    }
-                    else if (Def != Def0)
-                    {
-                        Unknown();
-                        return;
-                    }
-                }
-                if (Def0) { TerrainOps = &Def0->TerrainOperations; }
-            }
-
             const uint32 LV = Ctx.LayoutVersion;
             auto IsSharedCacheCurrent = [&]() -> bool
             {
@@ -5085,7 +5130,8 @@ namespace
                         CacheSearchMaxY,
                         P, SeedU, StrateIdx, true,
                         CacheSearchMinZ,
-                        CacheSearchMaxZ);
+                        CacheSearchMaxZ,
+                        TerrainOps);
                 const int64 MaxSharedChunkSpan = Ctx.Step >= 32 ? 32 : 16;
                 bool bUsedSharedCache = false;
                 const bool bTileWithinSharedBudget = bUseTileCacheWindow
@@ -6747,13 +6793,15 @@ namespace
                     {
                         VoxelCaveMorphology::BuildTunnelSupportFloorColumn(
                             static_cast<float>(World.X), static_cast<float>(World.Y),
-                            GetBoxCache(), EmptySupportColumn);
+                            GetBoxCache(), EmptySupportColumn,
+                            VoxelGenLOD::ShouldUseSpatialIndex(false));
                         SupportColumn = &EmptySupportColumn;
                     }
                     const FTunnelCoreWorldEvaluation Evaluation =
                         VoxelCaveMorphology::EvaluateTunnelCoreWorld(
                             static_cast<float>(World.X), static_cast<float>(World.Y),
-                            static_cast<float>(World.Z), GetBoxCache(), SupportColumn);
+                            static_cast<float>(World.Z), GetBoxCache(), SupportColumn,
+                            VoxelGenLOD::ShouldUseSpatialIndex(false));
                     ++B.ExactTailEvaluated;
                     if (!FMath::IsFinite(Evaluation.SDF))
                     {
@@ -8062,7 +8110,8 @@ namespace
             };
             VF_ForEachChunkSDFSpatialCandidate(
                 Rooms->GetCache().ColumnSpatialIndex,
-                Rooms->GetCache().Columns.Num(), WorldX, WorldY, EvaluateColumn);
+                Rooms->GetCache().Columns.Num(), WorldX, WorldY, EvaluateColumn,
+                VoxelGenLOD::ShouldUseSpatialIndex(false));
         }
 
         /** The cached column list is the complete source of this op's work.  A valid empty list is
diff --git a/Source/VoxelForge/Private/VoxelGenerator.cpp b/Source/VoxelForge/Private/VoxelGenerator.cpp
index 54a7827..f2ca025 100644
--- a/Source/VoxelForge/Private/VoxelGenerator.cpp
+++ b/Source/VoxelForge/Private/VoxelGenerator.cpp
@@ -56,15 +56,34 @@ namespace
         }
     }
 
-    // A tile-sized cache window is the production default.  Keep the switch in the generator
-    // module so native and op-stack sources make the same A/B decision, including when a
-    // headless harness applies command-line CVars after module startup.
+    // A tile-sized cache window is the production default on the coarse paths where it wins.
+    // Keep the switches in the generator module so native and op-stack sources make the same A/B
+    // decision, including when a headless harness applies command-line CVars after module startup.
     int32 GVoxelForgeTileCacheWindow = 1;
     FAutoConsoleVariableRef CVarVoxelForgeTileCacheWindow(
         TEXT("voxel.TileCacheWindow"),
         GVoxelForgeTileCacheWindow,
         TEXT("Use the requesting tile's aligned footprint plus the deterministic warp/halo margin for room caches."));
     bool GVoxelForgeTileCacheWindowSwitchParsed = false;
+    // Refreshed profiles put the fused crossover at LOD3 and the op-stack crossover at LOD4.
+    // Separate defaults keep a path that loses at LOD3 from paying for a larger candidate set.
+    int32 GVoxelForgeTileCacheWindowMinLOD = 3;
+    FAutoConsoleVariableRef CVarVoxelForgeTileCacheWindowMinLOD(
+        TEXT("voxel.TileCacheWindowMinLOD"),
+        GVoxelForgeTileCacheWindowMinLOD,
+        TEXT("Minimum SampleStep LOD for the fused tile-sized room cache window."));
+    int32 GVoxelForgeTileCacheWindowOpStackMinLOD = 4;
+    FAutoConsoleVariableRef CVarVoxelForgeTileCacheWindowOpStackMinLOD(
+        TEXT("voxel.TileCacheWindowOpStackMinLOD"),
+        GVoxelForgeTileCacheWindowOpStackMinLOD,
+        TEXT("Minimum SampleStep LOD for the op-stack tile-sized room cache window."));
+
+    int32 GVoxelForgeSpatialIndex = -1;
+    FAutoConsoleVariableRef CVarVoxelForgeSpatialIndex(
+        TEXT("voxel.SpatialIndex"),
+        GVoxelForgeSpatialIndex,
+        TEXT("Room-cache spatial broad phase: -1 measured auto policy, 0 off, 1 on."));
+    bool GVoxelForgeSpatialIndexSwitchParsed = false;
 
     void VF_ParseTileCacheWindowSwitch()
     {
@@ -80,6 +99,42 @@ namespace
             GVoxelForgeTileCacheWindow = CommandLineValue;
         }
         GVoxelForgeTileCacheWindow = GVoxelForgeTileCacheWindow != 0 ? 1 : 0;
+
+        int32 MinLODCommandLineValue = GVoxelForgeTileCacheWindowMinLOD;
+        if (FParse::Value(
+                FCommandLine::Get(), TEXT("voxel.TileCacheWindowMinLOD="),
+                MinLODCommandLineValue))
+        {
+            GVoxelForgeTileCacheWindowMinLOD = MinLODCommandLineValue;
+        }
+        GVoxelForgeTileCacheWindowMinLOD = FMath::Clamp(
+            GVoxelForgeTileCacheWindowMinLOD, 0, 5);
+
+        int32 OpStackMinLODCommandLineValue = GVoxelForgeTileCacheWindowOpStackMinLOD;
+        if (FParse::Value(
+                FCommandLine::Get(), TEXT("voxel.TileCacheWindowOpStackMinLOD="),
+                OpStackMinLODCommandLineValue))
+        {
+            GVoxelForgeTileCacheWindowOpStackMinLOD = OpStackMinLODCommandLineValue;
+        }
+        GVoxelForgeTileCacheWindowOpStackMinLOD = FMath::Clamp(
+            GVoxelForgeTileCacheWindowOpStackMinLOD, 0, 5);
+    }
+
+    void VF_ParseSpatialIndexSwitch()
+    {
+        if (GVoxelForgeSpatialIndexSwitchParsed)
+        {
+            return;
+        }
+        GVoxelForgeSpatialIndexSwitchParsed = true;
+        int32 CommandLineValue = GVoxelForgeSpatialIndex;
+        if (FParse::Value(
+                FCommandLine::Get(), TEXT("voxel.SpatialIndex="), CommandLineValue))
+        {
+            GVoxelForgeSpatialIndex = CommandLineValue;
+        }
+        GVoxelForgeSpatialIndex = FMath::Clamp(GVoxelForgeSpatialIndex, -1, 1);
     }
 
 }
@@ -460,10 +515,18 @@ void VoxelGenLOD::SetThreadSampleStep(int32 Value)
     SampleStep = Value;
 }
 
-bool VoxelGenLOD::IsTileCacheWindowEnabled()
+bool VoxelGenLOD::IsTileCacheWindowEnabled(bool bFusedPath)
 {
     VF_ParseTileCacheWindowSwitch();
-    return GVoxelForgeTileCacheWindow != 0;
+    if (GVoxelForgeTileCacheWindow == 0)
+    {
+        return false;
+    }
+    const int32 RequiredMinLOD = bFusedPath
+        ? GVoxelForgeTileCacheWindowMinLOD
+        : GVoxelForgeTileCacheWindowOpStackMinLOD;
+    const int32 RequiredStep = 1 << FMath::Clamp(RequiredMinLOD, 0, 5);
+    return FMath::Max(SampleStep, 1) >= RequiredStep;
 }
 
 bool VoxelGenLOD::GetThreadTileCacheWindow(
@@ -485,6 +548,25 @@ bool VoxelGenLOD::GetThreadTileCacheWindow(
         && Extent <= static_cast<int64>(CHUNK_SIZE) * 64;
 }
 
+bool VoxelGenLOD::ShouldUseSpatialIndex(bool bFusedPath)
+{
+    VF_ParseSpatialIndexSwitch();
+    if (GVoxelForgeSpatialIndex >= 0)
+    {
+        return GVoxelForgeSpatialIndex != 0;
+    }
+
+    // The full game sweep makes the fused LOD0 floor faster without the broad phase.  Keep it
+    // enabled for LOD1+ where the candidate reduction pays for GetRange, and keep the measured
+    // op-stack policy enabled at every tested LOD.  The explicit override remains useful for
+    // field/determinism A/B runs.
+    if (bFusedPath && FMath::Max(SampleStep, 1) <= 1)
+    {
+        return false;
+    }
+    return true;
+}
+
 // NOTE (T2.a): the fBm/Ridged bodies moved to VoxelNoise.h, where octaves are evaluated
 // 4-wide via SSE (Perlin3D_x4). These thin wrappers keep every call site unchanged. They
 // sample a DIFFERENT (float hash-gradient) noise field than the old FMath::PerlinNoise3D,
@@ -1244,7 +1326,8 @@ namespace
 
     static void BuildTunnelSupportColumnsForChunk(
         FChunkSDFCache& Cache,
-        const FIntVector& ChunkCoord);
+        const FIntVector& ChunkCoord,
+        bool bUseSpatialIndex);
 
     static const FTunnelSupportFloorColumn* FindTunnelSupportColumn(
         const FChunkSDFCache& Cache,
@@ -1353,10 +1436,16 @@ namespace
         FIntVector RequestedTileOrigin = FIntVector::ZeroValue;
         int32 RequestedTileStep = 1;
         int32 RequestedTileCells = 0;
-        const bool bUseTileCacheWindow = VoxelGenLOD::IsTileCacheWindowEnabled()
+        const TArray<FStrateTerrainOpEntry>* TerrainOps = nullptr;
+        if (UVoxelStrateDefinition* Def = Manager.GetStrateForChunk(ChunkCoord))
+        {
+            TerrainOps = &Def->TerrainOperations;
+        }
+        const bool bUseTileCacheWindow = VoxelGenLOD::IsTileCacheWindowEnabled(true)
             && VoxelGenLOD::GetThreadTileCacheWindow(
                 RequestedTileOrigin, RequestedTileStep, RequestedTileCells)
-            && VoxelCaveMorphology::IsRoomGraphWindowInvariant(Params);
+            && VoxelCaveMorphology::IsRoomGraphWindowInvariant(Params, TerrainOps);
+        const bool bUseSpatialIndex = VoxelGenLOD::ShouldUseSpatialIndex(true);
         const int32 StrateIndex = Manager.GetStrateIndex(
             (static_cast<float>(ChunkCoord.Z) + 0.5f)
             * static_cast<float>(CHUNK_SIZE) * VOXEL_SIZE);
@@ -1382,7 +1471,8 @@ namespace
             // density cursor crosses a chunk; the room/tunnel graph itself is not rebuilt.
             if (OutState.SupportChunk != ChunkCoord)
             {
-                BuildTunnelSupportColumnsForChunk(OutState.Cache, ChunkCoord);
+                BuildTunnelSupportColumnsForChunk(
+                    OutState.Cache, ChunkCoord, bUseSpatialIndex);
                 OutState.SupportChunk = ChunkCoord;
             }
             OutState.Chunk = ChunkCoord;
@@ -1421,7 +1511,7 @@ namespace
             StrateIndex, nullptr,
             ERoomGraphBuildSite::GeneratorTunnelCore);
         BuildTunnelSupportColumnsForChunk(
-            OutState.Cache, ChunkCoord);
+            OutState.Cache, ChunkCoord, bUseSpatialIndex);
         OutState.OwnerId = OwnerId;
         OutState.ManagerLifetimeId = ManagerLifetimeId;
         OutState.Chunk = ChunkCoord;
@@ -1440,7 +1530,8 @@ namespace
 
     static void BuildTunnelSupportColumnsForChunk(
         FChunkSDFCache& Cache,
-        const FIntVector& ChunkCoord)
+        const FIntVector& ChunkCoord,
+        bool bUseSpatialIndex)
     {
         const int32 MinX = ChunkCoord.X * CHUNK_SIZE - 1;
         const int32 MinY = ChunkCoord.Y * CHUNK_SIZE - 1;
@@ -1463,7 +1554,8 @@ namespace
                     static_cast<float>(MinX + X),
                     static_cast<float>(MinY + Y),
                     Cache,
-                    Column);
+                    Column,
+                    bUseSpatialIndex);
                 if (Column.Intervals.Num() == 0)
                 {
                     continue;
@@ -1805,7 +1897,8 @@ float UVoxelGenerator::GetDensityAt(float WorldX, float WorldY, float WorldZ) co
         FIntVector RequestedTileOrigin = FIntVector::ZeroValue;
         int32 RequestedTileStep = 1;
         int32 RequestedTileCells = 0;
-        const bool bTileCacheContext = VoxelGenLOD::IsTileCacheWindowEnabled()
+        const bool bTileCacheContext = VoxelGenLOD::IsTileCacheWindowEnabled(
+            !bShareTunnelStackByZ)
             && VoxelGenLOD::GetThreadTileCacheWindow(
                 RequestedTileOrigin, RequestedTileStep, RequestedTileCells);
         FVoxelOpStack* ActiveOpStack = &CP_OpStack;
@@ -2352,7 +2445,9 @@ float UVoxelGenerator::GetDensityAt(float WorldX, float WorldY, float WorldZ) co
             VoxelDensityProfile::FScopedTimer ProfileTimer(
                 VoxelDensityProfile::EBucket::TunnelCorePosts);
             PreDisturbanceTunnelCore = VoxelCaveMorphology::EvaluateTunnelCoreWorld(
-                WorldX, WorldY, WorldZ, ActiveTunnelCoreCache->Cache, SupportColumn);
+                WorldX, WorldY, WorldZ, ActiveTunnelCoreCache->Cache, SupportColumn,
+                VoxelGenLOD::ShouldUseSpatialIndex(
+                    CP_UseOpStack ? bUsedFusedEvaluator : true));
             bHavePreDisturbanceTunnelCore = true;
         }
         const bool bProtectAuthoredTunnelFloor = bHavePreDisturbanceTunnelCore
@@ -2499,7 +2594,9 @@ float UVoxelGenerator::GetDensityAt(float WorldX, float WorldY, float WorldZ) co
                     VoxelDensityProfile::EBucket::TunnelCorePosts);
                 TunnelCore = VoxelCaveMorphology::EvaluateTunnelCoreWorld(
                     WorldX, WorldY, WorldZ, ActiveTunnelCoreCache->Cache,
-                    SupportColumn);
+                    SupportColumn,
+                    VoxelGenLOD::ShouldUseSpatialIndex(
+                        CP_UseOpStack ? bUsedFusedEvaluator : true));
                 bHaveTunnelCore = true;
             }
             if (bHaveTunnelCore)
@@ -2831,15 +2928,27 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
     thread_local int32 CachedTileCells = 0;
     thread_local uint64 CachedManagerLifetimeId = 0;
     thread_local const TArray<FStrateTerrainOpEntry>* CachedTerrainOps = nullptr;
+    // The envelope proof is constant for a cache-policy key.  Do not run the complete room/edge
+    // reach calculation for every density sample: that would turn a build-time guard into a
+    // per-sample cost on the LOD0 floor.
+    thread_local bool CachedTilePolicyValid = false;
+    thread_local bool CachedTilePolicyResult = false;
+    thread_local bool CachedTilePolicyHasContext = false;
+    thread_local bool CachedTilePolicyFusedPath = false;
+    thread_local int32 CachedTilePolicySampleStep = 0;
+    thread_local FIntVector CachedTilePolicyOrigin = FIntVector::ZeroValue;
+    thread_local int32 CachedTilePolicyStep = 0;
+    thread_local int32 CachedTilePolicyCells = 0;
+    thread_local uint32 CachedTilePolicyFingerprint = 0xFFFFFFFFu;
+    thread_local uint32 CachedTilePolicyLayout = 0xFFFFFFFFu;
+    thread_local uint64 CachedTilePolicyManagerLifetimeId = 0;
+    thread_local const TArray<FStrateTerrainOpEntry>* CachedTilePolicyTerrainOps = nullptr;
 
     const bool bUseFusedCacheWindow = OutTunnelCore != nullptr;
+    const bool bUseSpatialIndex = VoxelGenLOD::ShouldUseSpatialIndex(bUseFusedCacheWindow);
     FIntVector RequestedTileOrigin = FIntVector::ZeroValue;
     int32 RequestedTileStep = 1;
     int32 RequestedTileCells = 0;
-    const bool bUseTileCacheWindow = VoxelGenLOD::IsTileCacheWindowEnabled()
-        && VoxelGenLOD::GetThreadTileCacheWindow(
-            RequestedTileOrigin, RequestedTileStep, RequestedTileCells)
-        && VoxelCaveMorphology::IsRoomGraphWindowInvariant(Params);
     const uint64 CurrentManagerLifetimeId = StrateManager
         ? StrateManager->GetCacheLifetimeId() : 0;
     const int32 QueryChunkX = FMath::FloorToInt(WorldX / (float)CHUNK_SIZE);
@@ -2865,6 +2974,39 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
                 QueryChunkZ));
         if (Def) TerrainOps = &Def->TerrainOperations;
     }
+    const bool bTileWindowEligible = VoxelGenLOD::IsTileCacheWindowEnabled(
+        bUseFusedCacheWindow);
+    const bool bHasTileWindowContext = VoxelGenLOD::GetThreadTileCacheWindow(
+        RequestedTileOrigin, RequestedTileStep, RequestedTileCells);
+    const bool bTilePolicyKeyChanged =
+        !CachedTilePolicyValid
+        || CachedTilePolicyHasContext != (bTileWindowEligible && bHasTileWindowContext)
+        || CachedTilePolicyFusedPath != bUseFusedCacheWindow
+        || CachedTilePolicySampleStep != RequestedTileStep
+        || CachedTilePolicyOrigin != RequestedTileOrigin
+        || CachedTilePolicyStep != RequestedTileStep
+        || CachedTilePolicyCells != RequestedTileCells
+        || CachedTilePolicyFingerprint != ParamsFingerprint
+        || CachedTilePolicyLayout != LayoutVersion
+        || CachedTilePolicyManagerLifetimeId != CurrentManagerLifetimeId
+        || CachedTilePolicyTerrainOps != TerrainOps;
+    if (bTilePolicyKeyChanged)
+    {
+        CachedTilePolicyValid = true;
+        CachedTilePolicyHasContext = bTileWindowEligible && bHasTileWindowContext;
+        CachedTilePolicyFusedPath = bUseFusedCacheWindow;
+        CachedTilePolicySampleStep = RequestedTileStep;
+        CachedTilePolicyOrigin = RequestedTileOrigin;
+        CachedTilePolicyStep = RequestedTileStep;
+        CachedTilePolicyCells = RequestedTileCells;
+        CachedTilePolicyFingerprint = ParamsFingerprint;
+        CachedTilePolicyLayout = LayoutVersion;
+        CachedTilePolicyManagerLifetimeId = CurrentManagerLifetimeId;
+        CachedTilePolicyTerrainOps = TerrainOps;
+        CachedTilePolicyResult = CachedTilePolicyHasContext
+            && VoxelCaveMorphology::IsRoomGraphWindowInvariant(Params, TerrainOps);
+    }
+    const bool bUseTileCacheWindow = CachedTilePolicyResult;
 
     // Index of the room with the smallest (most-inside) SDF for this voxel.
     // Written by EvaluateSDFCached, read by the terrain ops block to pick the
@@ -2989,7 +3131,8 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
         CaveSDF = VoxelCaveMorphology::EvaluateSDFCached(
             WarpedX, WarpedY, WarpedZ,
             SDFCache, Params.SDFBlendRadius,
-            &NearestRoomIdx
+            &NearestRoomIdx,
+            bUseSpatialIndex
         );
 
         // ── PIT & CHIMNEY SDF INTEGRATION ──
@@ -3039,7 +3182,8 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
             CaveSDF = VoxelSDF::SmoothMin(CaveSDF, PitSDF, Pit.BlendK);
         };
         VF_ForEachChunkSDFSpatialCandidate(
-            SDFCache.PitSpatialIndex, SDFCache.Pits.Num(), WorldX, WorldY, EvaluatePit);
+            SDFCache.PitSpatialIndex, SDFCache.Pits.Num(), WorldX, WorldY, EvaluatePit,
+            bUseSpatialIndex);
 
         auto EvaluateChimney = [&](int32 ChimneyIndex)
         {
@@ -3071,7 +3215,7 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
         };
         VF_ForEachChunkSDFSpatialCandidate(
             SDFCache.ChimneySpatialIndex, SDFCache.Chimneys.Num(),
-            WorldX, WorldY, EvaluateChimney);
+            WorldX, WorldY, EvaluateChimney, bUseSpatialIndex);
 
         // Convert SDF to density carving:
         // CaveSDF < 0 means we're inside a room/tunnel/pit → carve to air
@@ -3102,7 +3246,7 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
         // The interpreted source has a lazy worker LRU for block evaluation; building that table
         // here would turn a cache-window change into hundreds of unnecessary column builds.
         *OutTunnelCore = VoxelCaveMorphology::EvaluateTunnelCoreWorld(
-            WorldX, WorldY, WorldZ, SDFCache, nullptr);
+            WorldX, WorldY, WorldZ, SDFCache, nullptr, bUseSpatialIndex);
     }
 
     //=========================================================================
@@ -3328,9 +3472,11 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
             // We use the cached SDF so this costs two extra SDF evaluations per voxel,
             // only when near a surface — the common case is cheap (DistFromSurface > TerraceRange).
             float SDF_Zp1 = VoxelCaveMorphology::EvaluateSDFCached(
-                WorldX, WorldY, WorldZ + 1.0f, SDFCache, Params.SDFBlendRadius);
+                WorldX, WorldY, WorldZ + 1.0f, SDFCache, Params.SDFBlendRadius,
+                nullptr, bUseSpatialIndex);
             float SDF_Zm1 = VoxelCaveMorphology::EvaluateSDFCached(
-                WorldX, WorldY, WorldZ - 1.0f, SDFCache, Params.SDFBlendRadius);
+                WorldX, WorldY, WorldZ - 1.0f, SDFCache, Params.SDFBlendRadius,
+                nullptr, bUseSpatialIndex);
             float GZ = (SDF_Zp1 - SDF_Zm1) * 0.5f;
             // Normalized vertical component: 1 = perfectly horizontal surface (floor/ceiling)
             //                               0 = perfectly vertical surface (wall)
@@ -3620,7 +3766,8 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
         }
     };
     VF_ForEachChunkSDFSpatialCandidate(
-        SDFCache.ColumnSpatialIndex, SDFCache.Columns.Num(), WorldX, WorldY, EvaluateColumn);
+        SDFCache.ColumnSpatialIndex, SDFCache.Columns.Num(), WorldX, WorldY, EvaluateColumn,
+        bUseSpatialIndex);
 
     //=========================================================================
     // STEP 4g: DOMES (room-relative hemispherical ceilings)
@@ -3881,7 +4028,7 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
         // GetDensityWithParams retain this historical tail; GetDensityAt skips it and applies the
         // same predicates once in its common MC-space post section below both generation paths.
         const bool bTunnelSupportFloor = VoxelCaveMorphology::IsTunnelSupportFloorWorldPoint(
-            WorldX, WorldY, WorldZ, SDFCache);
+            WorldX, WorldY, WorldZ, SDFCache, bUseSpatialIndex);
         // Keep the direct legacy entry point capability-safe for callers outside the canonical
         // operator-stack path; its support band follows the same relieved swept floor.
         if (bTunnelSupportFloor)
@@ -3899,7 +4046,8 @@ float UVoxelGenerator::GetDensityWithParams(float WorldX, float WorldY, float Wo
             Density = FMath::Max(Density, StructuralSolidDensity);
         }
         const float TunnelCoreSDF = (Params.RoomDensity > 0.0f && Params.RoomSpacing > 0.0f)
-            ? VoxelCaveMorphology::EvaluateTunnelCoreWorldSDF(WorldX, WorldY, WorldZ, SDFCache)
+            ? VoxelCaveMorphology::EvaluateTunnelCoreWorldSDF(
+                WorldX, WorldY, WorldZ, SDFCache, bUseSpatialIndex)
             : FLT_MAX;
         if (!bTunnelSupportFloor
             && TunnelCoreSDF < -VoxelPassageGeometry::CaveTunnelAirCoreInsetVoxels)
diff --git a/Source/VoxelForge/Private/VoxelStackSampler.cpp b/Source/VoxelForge/Private/VoxelStackSampler.cpp
index e25caee..339c555 100644
--- a/Source/VoxelForge/Private/VoxelStackSampler.cpp
+++ b/Source/VoxelForge/Private/VoxelStackSampler.cpp
@@ -735,6 +735,8 @@ struct FStoredSample
             const FResolvedProgramCounter* LeafEntry = nullptr;
             const FResolvedSymbol* LeafFunction = nullptr;
             const FResolvedSymbol* LeafSource = nullptr;
+            uint64 LeafProgramCounter = 0;
+            bool bHasLeafProgramCounter = false;
             bool bSampleHasResolvedLeaf = false;
             bool bSampleHasWaitLike = false;
 
@@ -755,8 +757,8 @@ struct FStoredSample
                     }
                     if (FrameIndex == 0)
                     {
-                        LeafEntry = Entry;
-                        LeafFunction = FrameFunction;
+                        LeafProgramCounter = ProgramCounter;
+                        bHasLeafProgramCounter = true;
                         bSampleHasResolvedLeaf = true;
                     }
                 }
@@ -769,12 +771,8 @@ struct FStoredSample
                 {
                     if (FrameIndex == 0)
                     {
-                        LeafEntry = Entry;
-                        if (LeafFunction == nullptr)
-                        {
-                            LeafFunction = FirstFunctionSymbol(*Entry);
-                        }
-                        LeafSource = FirstSourceSymbol(*Entry);
+                        LeafProgramCounter = ProgramCounter;
+                        bHasLeafProgramCounter = true;
                     }
                     for (const FResolvedSymbol& Symbol : Entry->Symbols)
                     {
@@ -792,9 +790,17 @@ struct FStoredSample
                 }
             }
 
-            if (LeafEntry != nullptr && LeafSource == nullptr)
+            // SymbolCache is a TMap. FindOrAdd while resolving later frames may rehash it, so
+            // pointers captured during the loop are not stable. Re-find the leaf only after all
+            // PCs for this sample have been inserted.
+            if (bHasLeafProgramCounter)
             {
-                LeafSource = FirstSourceSymbol(*LeafEntry);
+                LeafEntry = SymbolCache.Find(LeafProgramCounter);
+                if (LeafEntry != nullptr)
+                {
+                    LeafFunction = FirstFunctionSymbol(*LeafEntry);
+                    LeafSource = FirstSourceSymbol(*LeafEntry);
+                }
             }
 
             auto AddToAggregate = [&](FProfileAggregateSet& Aggregate)
diff --git a/Source/VoxelForge/Private/VoxelWorld.cpp b/Source/VoxelForge/Private/VoxelWorld.cpp
index 4040d51..01a870f 100644
--- a/Source/VoxelForge/Private/VoxelWorld.cpp
+++ b/Source/VoxelForge/Private/VoxelWorld.cpp
@@ -3849,9 +3849,21 @@ void AVoxelWorld::GenerateTileResult(const FVoxelTileKey& Tile, const FIntVector
                 return bMeasureTile && TileProfileEnd.Counters[Index] >= TileProfileStart.Counters[Index]
                     ? TileProfileEnd.Counters[Index] - TileProfileStart.Counters[Index] : 0;
             };
+            const auto CycleDelta = [&](VoxelDensityProfile::EBucket Bucket) -> uint64
+            {
+                const int32 Index = static_cast<int32>(Bucket);
+                return bMeasureTile && TileProfileEnd.Cycles[Index] >= TileProfileStart.Cycles[Index]
+                    ? TileProfileEnd.Cycles[Index] - TileProfileStart.Cycles[Index] : 0;
+            };
+            const double TileSeconds = FPlatformTime::Seconds() - TileStartSeconds;
+            const double CacheBuildSeconds = FPlatformTime::ToSeconds64(
+                CycleDelta(VoxelDensityProfile::EBucket::RoomGraphBuild));
+            const double EvaluationSeconds = FMath::Max(
+                0.0, TileSeconds - CacheBuildSeconds);
             UE_LOG(LogTemp, Display,
                 TEXT("[VoxelForgeTileProfile] tile=(%d,%d,%d) level=%d step=%d cells=%d sheet=%d aborted=%d empty=%d "
                      "verdict=%d classify=%.6f mesh=%.6f streams=%.6f seconds=%.6f "
+                     "cache_build=%.6f evaluation=%.6f "
                      "refine=%u stack=%u core_samples=%u final_samples=%u core_hits=%u final_hits=%u "
                      "core_leaves=%u final_leaves=%u tail_queries=%u tail_eval=%u "
                      "stack_work=%.6f core_work=%.6f final_work=%.6f tail_work=%.6f "
@@ -3868,7 +3880,7 @@ void AVoxelWorld::GenerateTileResult(const FVoxelTileKey& Tile, const FIntVector
                 Tile.Coord.X, Tile.Coord.Y, Tile.Coord.Z, Tile.Level, Step, Cells,
                 bSheetTile ? 1 : 0, Result.bAborted ? 1 : 0,
                 Result.bEmpty ? 1 : 0, ClassifyVerdict, ClassifySeconds, MeshSeconds, StreamSeconds,
-                FPlatformTime::Seconds() - TileStartSeconds,
+                TileSeconds, CacheBuildSeconds, EvaluationSeconds,
                 ClassifierStats.RefineNodes, ClassifierStats.StackBoxCalls,
                 ClassifierStats.ExactCoreSamples, ClassifierStats.ExactFinalSamples,
                 ClassifierStats.ExactCoreCacheHits, ClassifierStats.ExactFinalCacheHits,
diff --git a/Source/VoxelForge/Public/VoxelCaveMorphology.h b/Source/VoxelForge/Public/VoxelCaveMorphology.h
index da3d388..60c8f6c 100644
--- a/Source/VoxelForge/Public/VoxelCaveMorphology.h
+++ b/Source/VoxelForge/Public/VoxelCaveMorphology.h
@@ -852,12 +852,13 @@ struct FChunkSDFSpatialIndex
 template <typename FVisit>
 FORCEINLINE int32 VF_ForEachChunkSDFSpatialCandidate(
     const FChunkSDFSpatialIndex& Index, int32 ItemCount,
-    float WorldX, float WorldY, FVisit&& Visit)
+    float WorldX, float WorldY, FVisit&& Visit,
+    bool bUseSpatialIndex = true)
 {
     int32 Begin = 0;
     int32 End = 0;
     int32 CandidateCount = 0;
-    if (Index.GetRange(WorldX, WorldY, Begin, End))
+    if (bUseSpatialIndex && Index.GetRange(WorldX, WorldY, Begin, End))
     {
         for (int32 Cursor = Begin; Cursor < End; ++Cursor)
         {
@@ -1008,14 +1009,16 @@ namespace VoxelCaveMorphology
         const FStrateGenerationParams& Params,
         uint32 Seed, int32 StrateIndex,
         bool bUseZ = false,
-        float SearchMinZ = 0.0f, float SearchMaxZ = 0.0f
+        float SearchMinZ = 0.0f, float SearchMaxZ = 0.0f,
+        const TArray<FStrateTerrainOpEntry>* TerrainOps = nullptr
     );
 
     // True only for the finite parameter envelope for which BuildChunkCache's fixed collect
     // margin proves window invariance. Callers may widen the XY store window to a whole tile only
     // when this returns true; malformed or unbounded authored input must retain the legacy path.
     VOXELFORGE_API bool IsRoomGraphWindowInvariant(
-        const FStrateGenerationParams& Params
+        const FStrateGenerationParams& Params,
+        const TArray<FStrateTerrainOpEntry>* TerrainOps = nullptr
     );
 
     // PHASE 2: Evaluate the SDF at a single world position using cached data.
@@ -1036,7 +1039,8 @@ namespace VoxelCaveMorphology
         float WorldX, float WorldY, float WorldZ,
         const FChunkSDFCache& Cache,
         float SDFBlendRadius,
-        int32* OutNearestRoomIdx = nullptr
+        int32* OutNearestRoomIdx = nullptr,
+        bool bUseSpatialIndex = true
     );
 
     // Evaluate the raw union of cached graph-tunnel capsules. This is intentionally separate from
@@ -1044,7 +1048,8 @@ namespace VoxelCaveMorphology
     // tunnel's walkable air core without reintroducing a connector or changing room ownership.
     VOXELFORGE_API float EvaluateTunnelCoreSDF(
         float WorldX, float WorldY, float WorldZ,
-        const FChunkSDFCache& Cache
+        const FChunkSDFCache& Cache,
+        bool bUseSpatialIndex = true
     );
 
     // Evaluate the final structural air contract against the world-space wandering chain. Room
@@ -1052,13 +1057,15 @@ namespace VoxelCaveMorphology
     // walkable floor follows the authored chain exactly.
     VOXELFORGE_API float EvaluateTunnelCoreWorldSDF(
         float WorldX, float WorldY, float WorldZ,
-        const FChunkSDFCache& Cache
+        const FChunkSDFCache& Cache,
+        bool bUseSpatialIndex = true
     );
 
     VOXELFORGE_API FTunnelCoreWorldEvaluation EvaluateTunnelCoreWorld(
         float WorldX, float WorldY, float WorldZ,
         const FChunkSDFCache& Cache,
-        const FTunnelSupportFloorColumn* SupportColumn = nullptr
+        const FTunnelSupportFloorColumn* SupportColumn = nullptr,
+        bool bUseSpatialIndex = true
     );
 
     // True for the finite support slab beneath a world-space graph tunnel. The native density
@@ -1066,7 +1073,8 @@ namespace VoxelCaveMorphology
     // the rounded capsule's bottom from becoming an unsupported point.
     VOXELFORGE_API bool IsTunnelSupportFloorWorldPoint(
         float WorldX, float WorldY, float WorldZ,
-        const FChunkSDFCache& Cache
+        const FChunkSDFCache& Cache,
+        bool bUseSpatialIndex = true
     );
 
     // Build/query the same support-floor predicate at column granularity. The column stores its
@@ -1075,7 +1083,8 @@ namespace VoxelCaveMorphology
     VOXELFORGE_API void BuildTunnelSupportFloorColumn(
         float WorldX, float WorldY,
         const FChunkSDFCache& Cache,
-        FTunnelSupportFloorColumn& OutColumn
+        FTunnelSupportFloorColumn& OutColumn,
+        bool bUseSpatialIndex = true
     );
 
     VOXELFORGE_API bool IsTunnelSupportFloorColumnZ(
diff --git a/Source/VoxelForge/Public/VoxelGenerator.h b/Source/VoxelForge/Public/VoxelGenerator.h
index ff183f7..cd5a0c4 100644
--- a/Source/VoxelForge/Public/VoxelGenerator.h
+++ b/Source/VoxelForge/Public/VoxelGenerator.h
@@ -63,7 +63,7 @@ namespace VoxelGenLOD
     VOXELFORGE_API void SetThreadOctaveBias(int32 Value);
     VOXELFORGE_API int32 GetThreadSampleStep();
     VOXELFORGE_API void SetThreadSampleStep(int32 Value);
-    VOXELFORGE_API bool IsTileCacheWindowEnabled();
+    VOXELFORGE_API bool IsTileCacheWindowEnabled(bool bFusedPath = true);
     VOXELFORGE_API bool GetThreadTileCacheWindow(
         FIntVector& OutOriginVoxels, int32& OutStep, int32& OutCellsPerAxis);
 
@@ -426,6 +426,13 @@ private:
                           const FBiomeContext& Ctx, FChunkBiomeCache& Cache) const;
 };
 
+namespace VoxelGenLOD
+{
+    // -1 uses the measured path/LOD policy; 0/1 force the spatial broad phase off/on for an A/B
+    // run. The policy affects candidate enumeration only, never cache contents or ordering.
+    VOXELFORGE_API bool ShouldUseSpatialIndex(bool bFusedPath);
+}
+
 /**
  * Optional diagnostics for one ClassifyTile call.  This is populated only when the caller asks
  * for it (the streaming profiler does); it is never consulted by the proof and cannot affect a