@thelostsoul yes, you and @mitu can all make me feel bad for the liberal use of sudo when I shouldn't :) You're right, I don't need sudo. I might have originally saved the collection files in a folder where the pi user didn't have write permissions, so that was that! Or I might have just been lazy about it - also likely.

Yeah, there's no issue with the platform you use, by all means - though you can install RetroPie on a Linux machine as well! A Pi3 is certainly a viable option, though with the Pi4 and the Pi5 - and especially with you playing on a Linux PC and a Steam Deck - the systems it supported are slightly self-contained by now.

No worries, I'm thinking of some developments on the EmulationStation front and this was a fun input that I had not considered. When I get around to it and publish them here I'll tag you.

Cheers, have a great weekend!