It’s been pointed out to me that while I have .sups, .subs, .numr, and .dnom figures in my fonts, they are not accessible via Unicode. Would it be worthwhile to add automatic Unicode numbers to such figures? Or is there too much controversy over whether .sups/.subs or .numr/.dnom should be assigned to those Unicode slots?
There are some unicodes for superiors and inferiors. If you like to use them, use the appropriate names (onesuperior).
Dot-suffixed glyph names imply OT variations, and should thus not have Unicode values.
OK, I made duplicates of the X.sups and named them Xsuperior; works like a charm. 
Thanks!