For non-Steam games, I do the same thing, either with Steam (by adding a non-steam game installer, and using proton to install it), or by using Lutris (https://lutris.net/). I generally use Lutris with my GoG library.
For non-Steam games, I do the same thing, either with Steam (by adding a non-steam game installer, and using proton to install it), or by using Lutris (https://lutris.net/). I generally use Lutris with my GoG library.