M2-only recomputation over all connected partitions (all basis pairs, no early stop):
  36 types with <= 7 vertices + 300 unlinked and 75 linked 9-vertex polytopes (random, seed 11)
  {'polytopes': 411, 'pairs': 207866, 'unlinked by M2': 323, 'linked by M2': 88, 'verdict differs from M1 run': 0}  (10 s)
