Hey. I think I have made a nicely working template for the KL49 + the MainStage 3.2.4 (sucks:). Gonna test it more this weekend. Would you like to get a copy? Should I share it on the web?
Mapped Bank 1 for controlling the Analog Lab and bank 2 for the Smart Controls (important!). Before that the buttons didn't move right (looks like MS still has some auto info somewhere and don't know what button is the right one). A playback per song (my choice) and something little extra for you to tweak more.. eg. a tap tempo and sound selection on the pads..
You know I am a musician. Obviously this is for my personal use so no time for guarantee nor support of any kind - but I think this work done might be helpful for others too - we should use our time making music, not writing code anyways. Let me know.
Cheers, Era