Two nudge shapes probed at 8c kernel scale (passive checkpoint at the pool
recycle boundary, fire-and-forget and awaited). The awaited shape reached
every §7a.7 shallow floor (read 16.6s, inserts 31.4s, deletes 50.0s) and
paid exactly what it saved (207.4s of attributed folds); fire-and-forget
regressed deletes 81→171s via fold/delete I/O contention while the
size-blind growth baseline kept the hard-cap parks firing on top (143
nudges, still 22 parks). All three arms within ~2.5% of each other — the
phase's fold I/O is a fixed budget the baseline already overlaps
off-thread, and the §7a.7 "~45s gap to the floor" is illusory. Code
reverted; #1362's valve + recycling remain the optimum of this family.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>