So the (putative) issue with the brow geometry plus the fact that the workaround for the blocky eyes breaks subdivision morphs makes me think I'll make the easy geometry changes a fair bit earlier than originally planned. By which I mean removing the brow overlays and toe caps, and fixing the topology of the eyes and breasts. Separate teeth are more work, so I'll still leave that for later, sorry primorge!

Given how well the fitting room works, there isn't really any reason to wait, either. I just had a quick try with an imported OBJ and everything seems to have transferred perfectly, including grouping, rigging, weight maps, JCMs and regular morphs.

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