I have made a small update. Have added an @Serialize section. Now the channel is no longer reset everytime you restart playback. So you can jump around in the piano roll MIDI editor and the Channel will be the same until you hit another keyswitch. A kind of latch effect.
Any bugs, let me know.
Link:
https://stash.reaper.fm/v/11328/Multi...DI%20Keyswitch