Any QMK based board that supports VIA should work, since the macros and key bindings are stored on the board, and you can use a browser to configure it (even if you have to configure it on another machine, and swap back to the Steam Deck).
Alternatively, I believe that Solaar is available in Discover Store for Steam Deck, and that would allow you to configure Logi devices (but I don’t have any personal experience with this yet).
Any QMK based board that supports VIA should work, since the macros and key bindings are stored on the board, and you can use a browser to configure it (even if you have to configure it on another machine, and swap back to the Steam Deck).
Alternatively, I believe that Solaar is available in Discover Store for Steam Deck, and that would allow you to configure Logi devices (but I don’t have any personal experience with this yet).