Message from your typical misanthropic neighbor:
If you happen to have an iPad, a camera connection set and a software like "MIDI Touch" (not written by me, for me or distributed by/for me etc.), you can create 25 Buttons (from -12..0..12) and let each send a MIDI SysEx message:
[F0 7F 00(up to 0F=MIDI channel) 04 04 00
34 F7] = -12
or [F0 7F 00 04 04 00
40 F7] = 0
or [F0 7F 00 04 04 00
4C F7] = +12
So the range is from 34..4C in hex digits.
It´s also in the Global.txt file and Midi implementation PDF on your Kronos disk.
Works in Prog,Combi,Global mode. At least that are the modes I just tested. This functionality will also be part of my Kronos support app. (+ and - buttons also), because you are not the first one to ask if this simple thing is possible. But it´s still in the works. Have to work harder. (This is not yet an advertisement!)
If you don´t have an iPad it´s of course not a cheap solution.
Sadly the nanoPad2 is not able to send SysEx or you could have used that. Would be nice to have Korg add that functionality.
And why the heck didn´t Korg include buttons for transpose on the Kronos/M3 surface anyway? Because it´s a workstation and not an Arranger? Why don´t we stop thinking in that obsolete categories?