Yes, that seems to be a better solution. I like the idea of having a script that could work both from within Poser or independently.

Just a little addition/correction: in addition to the "vt" lines, one would also need the middle parts of the face specifications in case the seams had changed. You know, if there was a line like "f 1/2/3 4/5/6 7/8/9" in the modified .obj file, one could write that out as, say, 'ft 2 5 8' in  the UVs file. Of course one would have to make sure that the order of faces in the original and the modified .obj file was the same.

-- I'm not mad at you, just Westphalian.