Could you somehow take an M3 mesh and "unwrap" it in a modeler so it could be placed piece by piece over an M4 template. Rendering this mesh orthogonally with the texture in the ambient channel would then possibly create an M4 texture. It is no easier I am sure then remapping the M4 the way David remaps his figures but maybe more do-able for people for whom modeling is a strong point.

Anyway, I find orthognal mapping is often "good enough" for full body or background figures. Could you render M3 in a frontal and then a back orthognal view posed properly and then match M4 to the pose and scale to use Group Tool perspective UV to skin that onto M4? Results would be way way crude but maybe good enough for background figures.

Just thinking...

Long ago there was an Photoshop action that converted Posette textures to Victoria 2 entirely in Photoshop. Be cool if anyone ever made a V3 to V4 or V4 to M4 Photoshop action. Certainly it is beyaond my ability.

Anton once indicated he could do texture conversions in Poser with some sort of sliced geometry or something but then he never revealed his method. Wish he had.

Is there a simple way for non-modelers to shrink wrap one figure to the geometry of another? Once saw a post by someone who actually achieved that in the Cloth Room... person was gonna let me in on the method but had too much real world stuff going on to make a tutorial.

Those are the methods/ideas that come to my mind from 10 years around here.

All this is kosher in my opinion for personal use  if you own both the target and source mesh though I am sure some people are touchy about such stuff. Sure wish Wardrobe Wizard just did a check for installed .obj files rather than having the head hands and feet locked!