Interesting observation - all 020+ versions of KingCON starting with 1.8 and up to Cosmos 40.4 crash with 8000 0004 (Illegal instruction) - can it be some rarely used 020+ instruction that is not implemented on the MIST 020 core?
Till has been doing some TG68 core tests, and it seems it has many issues that need to be fixed. Hopefully, most of those issues will be fixed in the future.
Though I can make it work with many keys, I struggle with ctrl, alt and GUI keys, or maybe I just got wrong USB keyboard IDs?
Yes, that might be a problem, since the modifier keys are treated somewhat specially. I'll take a look and see if something can be done for this.