FI/TN/VS (legacy compiled-analytic) skip ZERO tiles at every LOD and evaluate ~44k density points per LOD0/1 tile; SW skips 359/512 at LOD0. The whole-tile skip requires a native tile with a uniform verdict, and the legacy paths return Mixed/unknown (R39 notes attached). Opt-in stage timers, sampled field timer, per-LOD classification and composer counters. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1