I made a MIDI variant based on @DanThomas' multi-tap macro which works nicely, with one minor exception that's driving me bananas.
A separate macro is momentarily enabled and watches for MIDI key releases. It works fine, unless you trigger two single presses roughly 1.2sec apart. If you do, it doesn't register the second release and thinks the second is a "Long Press". There seems to be a small window of time where this error occurs, as faster or slower presses trigger perfectly. I have noticed that disabling the "Check for Multiple Taps" group fixes this, but obviously means that double/triple taps are off the table.
I've included here a testing macro that contains various MIDI trigger types, for convenience. It comes set to produce the aforementioned error, at least on my system. If your mac is quicker/slower than mine, you may need to adjust the timing.
If anyone can spot what's happening, please let me know.
MIDI Multi-Press Testing.kmmacros (164.0 KB)