I have that, actually.  It looks just a little odd on V5Supermodel with the leg to one side and bent (for e.g., in ballet poses) and it can't handle Stephanie 5 + Model Body at all.  I think it pretty much works on plain V5 or others that minimally change the thigh/knee proportions.

Perhaps it's just a limitation of the medium, or I need to do my own long legs bend fixer and release it as a freebie.