One rectangle via the multipatch path is bit-identical to the old single-patch blocked path (both modes, raw masks); S1 two-patch 16x32 equals the 16x16 one-patch run tiled (bitwise), in both rectangle orders; face gap-4 pair is order-invariant with exact covered/hole masks. Mass printed as a diagnostic only. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>