Hello! I just want to share that I've just managed to build Fallout-2CE and that it runs on Ryujinx. I need to figure out how to rig up the controls but so far music and videos work! I will continue working on it 🫡
I had the same issue, with the physical orientation of the switch being important (lying face down on the bench, it mostly worked). Likely due to the dat0 adaptor having only partial contact.
Solved it by doing kamikaze.
Plug it into a computer and use putty to get the error code.
Also consider it might actually be using hwfly diagnostics:
https://gbatemp.net/threads/switch-oled-modchip-blinking-red-and-not-launching.628523/#post-10100691