Ability to add functional chord symbols (e.g. I7, iii-7, etc.)??

I've tried to search for this to see if the question has already been asked, but no luck so far.

Basically I sometimes use MuseScore to write lead sheets; and in doing functional analysis of the harmony I want to be able to add standard chord symbols such as those in my topic title. Right now this doesn't work for me for two reasons:

1) MuseScore won't provide superscript for chord extensions (7, 9, etc.) when numbers are used (e.g. I for tonic, V for dominant, iii, etc.).; it only does this for chord letters (G, D, etc.).

2) I've attempted to duplicate and then rename/modify a new Chord Symbol style, using jazz fonts on my Mac that allow typing superscript and necessary symbols directly; but MuseScore defeats this. For example, if I type in a triangle symbol for "major" in the JazzCord font, this is changed to the letter "J" upon closing the text box.

If there is a workaround that anyone knows of, even if clumsy, I'm happy to use that. Otherwise I am going to have to start marking up PDFs exported from MuseScore in PDF software, which is of course a poor way to have to go.