I've had some luck with that #ATMega4808 board as far as getting an #ArduinoNano wired up as programmer and using the #JTAG2UPDI code to push a 4808-friendly bootloader onto the device.

A problem though has brought me back into the nuances of the #CH340 serial chip world, which I had hoped I was done with yrs ago.

Seems maybe older MacOS versions have probs with CH340K vs G vs other variants.

I'm still on BigSur though, so perhaps this is reason to increment up to Ventura.