Hello, I answered your question, via my review or your "almost" the same question->
https://www.digitec.ch/fr...
As far as the firmware is concerned, there is no adjustment to be made. The fact that the GMMK works in ISO CH is due to the fact that:
- The keyboard is in ISO layout, no need to worry about it more than that.
- The CH layout is to be set in the OS and not with respect to the keyboard settings itself. (the CH layout is ISO anyway)
- Keycaps are 100% compatible with the layout + ISO or ANSI layout specifications.