yeah that's how i did it. bit painful for when you only want to subdivide part of a mesh and have to clean up all the terminators for the additional loops you don't want.
This post totally slipped under my radar. Apologies. Anyway these are the control curves with profiles assigned, so in a way, yes you can use lines (poly curves) and convert them to haircards.Edge loops can be converted to Blender-native poly curves and back without data loss. So you can poly model shapes with edge loops…