Since tangency-labs/smlib#67 an extruded profile's arcs on one circle sweep one full-turn wall face, made from all of them (Profile 4, 5 and 6 here), where it was a face per arc. The geometric check of the record finds a face over several segments by its triangles' centres and vertices on them; the revolved arcs keep a face each. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>