The kernel runs exact helical sweeps and never resizes; the check that refuses a thread off its hole's or shaft's size is the engine's sugar (AGENTS.md). So the seven cases (995, 1443, 2152, 2969, 3366, 2369, 2705) go back to expecting that refusal and its message, as1375e905had them, reversing1588dd70. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>