I also have the 256gb Deck (LCD day one) and put all Roms on 512gb microSD card. :-) One positive thing about using the Steam version of RetroArch is to have builtin Cloud saves for every configuration and game saves, and playtimes. Also it does not clash with RetroDeck or Emudecks own shortcuts and settings in example. I’ve seen over and over reports of problems that can be traced back to that. On my Deck RetroArch has highest playtime too, right now at 180 hours. :-)

And the controls of F-Zero, it is definitely not easy and one need to get used to it. One tip I could give is, in the corners instead using break, I recommend to let go of acceleration very quickly, in a quick tapping manner until you get the curve. This gives you control and grip and reduced the speed. I actually improved playing like this and finished the cups, which I was not able to before.

One thing I enjoyed a lot (many hours, instead playing a game lol) is experimenting and creating custom controls, menus and functionality. I always wanted to share my RetroArch custom Steam controls (through Steam Input community share option), but that would require exact setup of some shortcuts.