I've been interested in using OpenMPT for MIDI hardware work, and I'd argue it's currently one of the best options for making MIDI files in a tracker interface. I know you've expressed that macros are not the solution for plugins, however (currently) they're the only solution for exporting a MIDI with Sysex messages. One of the problems with that, though, is the character limit; it sounds as though you can't change this due to file-related restrictions. So I have some questions before submitting a feature request:
1. Am I correct in my assumption that it would not be theoretically possible to use an unlimited number of characters for macro messages?
2. If possible, is it feasible?
3. Would it be possible to set custom "fill-in" values (such as "z" and "c") to get around this limit? Is there a limit on the length of the values they can represent?
Some advantadges of using the unused fill-in values I could foresee is that it allows you to re-use bytes such as the device ID fields without needing to increase the character limit. For example, in order to send data to my Roland D-110, I need to begin the sysex message with the same 4 bytes (or 8 characters) every time (excluding spaces): 41 10 16 12
If I could represent this with a user-defined lowercase value, I'd be able to use those 8 characters for the actual message data.
Apologies for the formatting issues, I'm on mobile.