There's your problem right there - instead of nuts and bolts, you should be using software. :-) Sorry, just couldn't resist that. ISOP's Catherine dress for V2 has a pose file called 'MDDress_leg_ConOFF' which apparently turns off the leg conforming so that posing can be done with morphs. I'm not clever enough to see what he's done in there, but it may be worth having a look.