During the time we were discussing this, the keyboard’s API was updated, which also affected the MC plugin. At first, my post contained the older version of the MC code (I think). Shortly after I updated the code to use the new API. That alone would not be enough to get it to work, though. The entire Kaleidoscope library, including most of the plugins, had to be updated as well, or the Keyboard would get stuck when using the newer MC code. Maybe this is why it didn’t work for you?
Edit: There were a few occasions when I couldn’t get my sketch code to work on my keyboard. I’d make a few, seemingly harmless changes, compile and upload, and the keyboard would get stuck. When I say stuck I mean that when I plug it in, the keyboard does not register anything and my operating system hangs for 5 seconds. I’d undo the changes, recompile and upload, but the problem would still persist. I have a non-working sketch code right now that worked just fine a month ago. Finding the problem is cumbersome, it entails me using a divide and conquer approach, basically cutting out parts of the code and see if it’ll work until I can pinpoint the exact line of code that’s causing this problem.
A tip: keep backups of your hex files.