I'm not yet sure what really happens if PML is used with new skinning.  With a bit luck the check is just overreacting. But its not easy to check. Many parts of the program are using the functions in question. My theory is that the figure skinning doesnt change the content of the figure, at least not morph-wise. You could make the morphs on a classic-skinned copy of your figures, and use the injection pose writer (and the new injection pose loader) script to copy the morph data into the figure with the unimesh skinning. Then you do not have to switch.