I was able to gather some python experience, thanks in any case Phil. What I already did was to make the posed-morph-loader, and now I think of exporting core .OBJ files with the joint centers contained in them as stand-alone-vertices so I can also just move them in an external modeller, and not having to worry about the joint-influence-zones. In my  understanding the use of vert maps locks the influence values to the vertices, and thus one can move them around in a modeller, without destroying the rig entirely.

E.g. I wanted to "blend" a weight-mapped V4 to a weight-mapped M4 and see what happens. Genesis for the poor, so to say.

As scaling seems to have some odd effects on bending in general, I thought scaling could be replaced by morphing the core geometry along with move of joint centers and using weightmaps.