A mystery about superior and inferior.
I created the superior and inferior glyphs from a to z. Now, if I compile something with Xe- or Lua-LaTeX like
everything is fine.
But if I write instead
that is using glyphs I present as lowercase but that I did not create even in the superscript version, in the text they do not appear.
But if I do the same thing with some other fonts that I've tried (EB Garamond, Garamond Premier Pro etc.), even if I didn't find those glyphs in the sups), they also appear in the superscript version.
Obviously I am missing something in the generation of these glyphs ...