In the article Korg M3: Controlling KARMA and other M3 functions with a foot controller, down in the Tips section, there is a note that "There is no CC number that will turn the DRUM TRACK on/off, but you can use sysex to do this."

This bit came from a post by Stephen Kay on the Karma-Lab forums, in Korg M3: General Discussions in this thread: Using a Midi Foot Controller to trigger Pads, Latch, Karma on/off.

However, Stephen didn't describe how this would be done; only that "It's a bit more involved…"

It would be great to flesh out this article with the details on how you can control the DRUM TRACK on/off via sysex—where do you go in the M3 to see the sysex command you need to configure on the midi foot controller?