For games that doesn’t support Steam Cloud for saves etc., or in general moving files over to the Steam Deck from your PC, I highly recommend setting up Syncthing.
It’s available on the Discover store in desktop mode and can be set up to run as a service to ensure that it’s always running on Steam Deck, if you’re so inclined. There’s a myriad of guides out there if you search around, should you need help setting it up.
Just as far fetched, yes.