GUV tiles are just mapping by polygon (where each polygon is broke off from the whole and UV mapped) if I recall. So yes, Poser would likely support that but your end users will hate you for the rest of your natural existence.

Poser allows for partial subdivision via bodyparts. For example, if you don't want the eyeballs to subdivide along with the body you simply select the eye, go to the properties for it and choose Subdivide separately from figure. If it's a prop, it gets tricky. I don't know if Daz Studio supports partial subdivision.  Poser does not currently support PTex.