A custom PCB checker overestimated corner clearance by up to 0.4 mm because it did not sample Edge.Cuts arcs, back-side 3D models were double-flipped, and its own check reported 0 violations while KiCad DRC in CI still was not green.
From the Grok pain-radar digest, Oct 24-25 2026 (Oct 24 evening to Oct 25 morning slots). Verified live 2026-10-25: issue/PR read on GitHub; title and state confirmed.