The round-3 'field contact error' measured hit-to-anchor distance; V2 contacts are 0 cm and on the zero isosurface. Tagged-tile cost 5.7-6.7x -> 1.175-1.270x MC; organic 0.998x. Bound, shelf-thickness and route audits rerun with negative controls; W1/W8/W16 stable; V1 and MarchingCubesV1 unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ