how to alter chords_jazz.xml to superscript "ma"

Hmm, I thought I responded but it seems to have disappeared?

Something like this should work, but may require further experimentation:

<token class="quality">
<name>ma</name>
<render>m:0:-3.0 m a m:0:3.0</render>
</token>

The idea is, you're recognizing "ma" when it occurs as a chord quality (as opposed to when it appears as a modifier, like in Cmi(ma7), and rendering in with a Y offset of -3, using the letters m and a directly. With this you shouldn't also need your other change.

FWIW, while superscripting the ma is done in some handwritten manuscripts, it isn't recommended by most publishers. The Brandt/Roemer standard - which is more or less what we follow - specifically calls for these to be on the baseline (and to be small caps). If this is for the Open Music Theory project, I'd recommend using the Brandt/Roemer standard, since it is the closest thing there is to an "official" correct way, and it is followed by more major publishers than any other system.

To the extent we fail to adhere to Brandt/Roemer in places, those are the customizations I'd be recommending - to bring us closer, not further, from the standard. In particular, one thing you might try is stacking the alterations. It's probably the most notable thing we should do but don't, because it's hard to get this right in all cases. But, if you don't mind hacking the XML file, you can get it for the cases you need, using those m:x:y directives.

I've attached an XML file I put together that does try to automate it for specific pairs of extensions enclosed in parentheses - see the rules at the bottom of the file. I also tried to make a rule to do this semi-automatically for other combinations if you enclose them in square brackets (they'll be turned into parentheses automatically).