You could try weylus. It works but it has delay.

Yep thanks Yahoo, disgusting… Donated some so that they can pay the employes and thinking about getting a metager key.

So I have no clue about the Steamdeck but as far as I know there should be a desktop mode. Maybe you can than install Lutris which has the possibility to include GOG games.

Very nice. Searched some time for a GW replacement but none fullfilled my needs like this!