On OCCT 8, parallel Boolean operations race on shape flags in 60 of 60 parallel runs under ThreadSanitizer, so FreeCAD runs them serially and a 50-cylinder fuse takes about 2.2x as long.
From the Grok pain-radar digests, Nov 1-2 2026 (Nov 1 8:41 AM ET through Nov 2 7:41 AM ET digests plus the Haitch editions). Verified live 2026-11-02: issue/PR read; title and state confirmed.