Just a note: There's no reason why one couldn't remap the base models, that I know of. V4/M4/K4 all use the same mesh, AFAIK. Copy the original base .obj model, rename it so it doesn't replace your original model, then take that copy and remap it. Edit the CR2 to reflect the new reference .obj for the remapped model and, walla, have fun applying whatever textures for that geometry that you wish. (Some texture poses may not work, but that won't keep you from applying the textures to the model by hand, if necessary.)

Note: I've done it, but I've never done it with M4, though I probably should have tried it before posting this. :D I don't have the script mentioned, either, so I don't know how it works. I would imagine it just uses the CR2s as references, so you can control what specific .obj file those reference and remapped geometry, I also assume, is not going to effect the script being run. It's still the same geometry, just with a new UVmap that still obeys the same groupings.