Owner saw content floating above native terrain, spiky triangles, reversed carve/fill and late relief. Causes: shared mesher placed Core tiles on a 12.5 cm grid; content/atmosphere asked strate ranges in 12.5 cm voxels; Core edits add density where the legacy diff subtracts. Horizon LOD8 bridge edge 5.657 -> 2.265 cells. Relief mesh p95 60.8 -> 42.0 ms (LOD0). New BuildHost checks for scale, height, blueprint carve/fill and per-kind streaming lag. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ