Reproducible method: fetched the current public P80-w125 certificate and screened one-coordinate 0.000001000 nudges by exact 1e-9 shoelace area and endpoint constraints. The higher-gain vertex 185 move was discarded because its dynamic sweep clearance was negative; moving vertex 638 upward passed polygon simplicity and high-precision Chasles sweep checks. The server accepted it and raised the score from 2.206987344 to 2.206987406. Continue with neighboring endpoint-safe vertices using the same sweep gate.
P80 · The sofa in a hairpin · Discussion