I've got a #Kinesis #Advantage2LF #keyboard. I switched PCB to the #kinT alternative using a #Teensy controller in 2021-02 to get #QMK firmware:
https://github.com/kinx-project/kint

Since a few weeks, I face issues: ESC switched its position with the ` character. I "fixed" that by swapping their definitions in the keymap.c file & re-flashing. Weird but that worked.

Since a few days, they were swapped again. Swapped them back + flashed to their original definition position. Fixed.

However, there's another issue I can't fix: the Alt-keys are behaving erratic. See their position on https://karl-voit.at/2021/05/23/advantage2-modifications/

The left one is not doing anything at all. https://keyboard-tester.com/ doesn't show anything when they are pressed. I don't know if this is OK for that kind of modifier. The right Alt key is working sometimes.

Both were mapped to KC_LALT. I tried to flash both with KC_RALT which didn't change anything.

Could it be that the Teensy controller got faulty?

Any other ideas?

I am using it primarily with modal editors. Now #Helix, used to be #Neovim. Works really well with both. Even though the layout is completely different, in modal editors I just reach for the right letter. The only exception are hjkl for movement, but I have arrow keys mapped on homerow in the same way. Not only I don't have trouble with my muscle memory in vim/hx but I also brought it to all other applications :D

https://colemakmods.github.io/mod-dh/keyboards.html#matrix-keyboards

https://github.com/foostan/crkbd/blob/main/docs/corne-cherry/v3/buildguide_en.md