1a4ef5c7a1
The entry reported an 'output-stability regression' as a novel run-2 finding. Both halves were false and the corrections are more instructive than the original conclusion, so they stay in-line rather than being edited over. Not new: run 1's own gate record already carried the same effect with a caveat attached and unresolved. Two runs across two different base models makes it a property of the RECIPE, not of the base swap -- which also means a third run that changes the base again will not fix it. Not degeneracy, and not a separate finding: all 46 flags were too_short rp turns of 3-14 words, and the two collapse guards fired ZERO times on any run. It is the left tail of a length distribution that had been measured and reported in the same message. Truncation is the same mechanism mirrored on the story side. Both are thresholds calibrated on the base's output shape applied to a model with a different one -- 4.6.1, which both parties had written down and neither applied. The surviving lesson is sharper: a short-answer gate cannot see length behaviour AT ALL, and because it could not, the effect went two full runs before anyone named it. The cost of a gate-set blind spot is measured in runs. Adds 4.6.3.1 on trip points inside the serving stack's jitter -- same seed, same weights, rate moves 9.6% -> 12.6%, sd 1.77pp. Not 'the gate is non-deterministic' but 'the trip point sits inside the jitter', because the fix follows from the precise statement. Includes the split-design rule for measuring such a rate, and the rule that a measured rate must carry its corpus in its name.