Yes, that works too with one fairly big caveat: for some reason the Steam Deck's controller is not producing evdev events until a game is actually running on the deck. So evfwd is not receiving events while the Steam UI is active. I haven't been able to figure out yet why this is the case.

If you want to try it you can start a random game on the deck and then fire up evfwd on the controller device and using the -g (grab) flag to avoid passing events to the running game.

Edit: while we are talking about the Steam Deck: when ssh-ing to the deck it can be helpful to turn off wifi power management to avoid lag: iw wlan0 set power_save off