So, I've written a fairly long-winded war log of debugging a stuck notes error that occurred when playing the NanoEgg prototype through my Twister controller box. It lives at: https://hackaday.io/project/8027-twister-a-play-on-midi-controllers/log/39746-debugging-stuck-notes

As it turns out, the problem wasn't in Twister at all, nor in the hardware as I suspected. It turned out that there was a bug in the MIDI libraries on the Teensy that had never been updated since version 3.2 (latest is 4.2).

But I got to spend some quality time with an oscilloscope I borrowed from 23b Shop, so it's all good!

I'm just happy that it's all been fixed now!