As far as I'm aware C3D does NOT have an automatic setting for rotating about the inside or outside edge. It only automatically supers about the CL; automatically at least. If you want to rotate about the inside \ outside edge you have to do it manually with offset alignments and profiles and figure out the transition lengths \ slopes yourself.
Not the end of the world but crazy since you are expecting it to just be a toggle. LDT had it and all you had to do was choose a method for rotation. I wrote this off as something forgotten and will be added as folks complain and versions are refined.