The best way to go about this might be to see if theres a way to completely load a new obj into a figure. Since the uvmap comes along with the obj, that might 'trick" poser into using a new uv map.

*I'm sure someone will come along and tell us this can already be done. I'd be interested to learn the technicalities. 

BTW, a script that could spare a content creator the technicalities would be valuable. This method would also allow the new UV map to include completely new boundaries.

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