@Maarten_Kruijswijk , just a point of forum history I recalled: if you decide to work up your own font symbol variants, there may be something in this thread from a few months back (started by @DanielMuzMurray, and with contributions from many, including the inimitable @FredGUnn — and I seem to recall you yourself were in on it) that might serve as a meaningful jumping-off point…?
Keep us posted on any font-mods you make, please, 'cause you know we’re always on the lookout for that perfect jazz chord font!