If you’re building your own font, you should be able to build a superscript character into one glyph, treating it like an accent or a vowel sign. You can also build in kerning, or have one unicode code point be replaced by a string of signs.
If you’re going to use it for multiple projects, it seems like a good investment of time.
However, everything about fonts, from licensing to recommended names for glyphs, seems overly complicated and rife with potential problems.