@Dave-So: Yep, that's pretty much it.

Look at XAA's reworked Posette. He did local subdivision and re-topolgize the joints to vastly improve Posette's bending.

I just stayed with V3/M3 because I'm lazy and because Colorcurvators' Morphloader gives me complete control over any type of mesh, regardless how "good" or "bad" the mesh topology actually is.

The technology to have realistic joints already is available, but I guess it's more lucrative to push a "new and improved" rigging system than to refine what's already out there.