I’m toying around with the M1 pitch bend command, but I can only do upwards bending, not downwards? 000 is no bend and 7F7F (and above) is maximum upwards bend, it seems. Am I missing something here?
With MIDI, the last change that was executed will stay in place for that Plugin/MIDI device. So in this case entering new notes doesn’t reset the pitch back to the middle again. You’d need to start with M1 4000 and then pitch down from there. This video shows that kind of thing in action (2:05).