Ch441 board A/B scanout comparison (2026-07-21)

Candidate Ch441 = 9463602d... : replay DONE rc=0, 311 drains, zero drops, FB SHA d0047677 (byte-identical golden). LPDDR_STATUS[5] SET ~15/16 (0xF1).
Accepted  Ch437 = 3dd624cd... : replay DONE rc=0, 311 drains. LPDDR_STATUS[5] SET 16/16 (0xF1) — SAME underflow.
Canonical retroDE_ps2.core.rbf = 56e45346... = Ch439b (previously REJECTED for this exact 0xF1).

VERDICT: both Ch441 and the ACCEPTED Ch437 underflow identically -> reproduced BASELINE scanout defect (LPDDR_STATUS[5]), NOT a Ch441 regression. Ch441 remains the timing-clean / renderer-correct candidate; scanout defect stays OPEN. Ch441 NOT promoted to canonical.