I have installed Bazzite on my Rog Ally and plan on using as my main gaming PC together with a XG Mobile 3080, but the command to enable supergfxctl to switch from GPU does not seem to exist although it is in the documentation
Bazzite is a custom image built upon Fedora Atomic Desktops that brings the best of Linux gaming to all of your devices.
Solution
I haven't tried it but you could try and rebase to the nvidia-deck image it will have both nvidia and amd drivers. It might work for a eGPU but I have no idea