I should have added that the new OBJ has different material zones than the original, since the seams changed and what was included with what changed too.
For example, there is no more "skinScalp", as the entire head is now one material group, aside from the lips and lacrimals still being separate.

Doing it that way, for one, eliminated seams on the head and separation of the head textures. It also makes it better when using nodes such as SSS, which can rely on a radius of influence; the head as one material acts as one material, as opposed to separate groups which each have to be tuned separately once the render engine sees them as separate groups. That may not be so in Poser, but it is an issue with other apps.

And the seams around the legs and arms are all different too - different material groups - and don't include any of the body UVs.