I once had the wild idea to make some suits of varying tightness, run simulations on them while the avatar makes the elementary arm and leg moves. Then from the vertex movements recorded find the location of the joint centres that best represent the motions, get weightmaps that best represent the vertex motions around the centres, and then finally find JCMs as the residuals by substracting the rig imposed motions from the ones determined by simulation. I decided to lock it up. Better for my sanity.