"More complicated would be an extra bone, not between existing bones as the V3 buttock is, but a spur which controls some of the elbow (or kneecap) mesh, and is driven by the motion of the main joint." Yeah, I tried that, I had a early version of Glamorous Jessi set up that way, more-or-less JCJ rather than JCM, with ghost (not physical) parts. Worked fine for the figure but I couldn't get it to work in conforming clothing. Oh well... I do think GJ bends pretty well, though, given the current state of the art. I'd love to see some non-biased person compare the bending of all the available figures.