The more I think of it:

A figure that can wear V4 wardrobe without any conversion, looks like V6/V7, uses V6/V7 textures (Or any other V4 texture), still bends in Poser just as well as V6/V7 does in Studio (The demo shots were done without any erc-fixes), might be just what most people actually want.

This is of course the V4 17k LOD mesh.

I'd have to test that rig with a V6/V7 mesh morphed into a V4 clone.