Okay, getting there. I've got a script that should do what I want but so far Poser isn't quite happy. So I'll be spending some time debugging. In the meantime, here's evidence that I can combine a subd-0 FBM morph with hi-res detail in a second morph to reproduce my original Blender sculpt. All that's missing is doing it all in a single morph.

 

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