Oh, I'm using Heroic for that too, it works well enough. But I was using GoG launcher before switching to Linux, even for Steam games and other storefronts. I would like to keep using it on Linux, hence my previous comment.

I appreciate the enormous work Valve has done for Linux gaming, but I'm also somewhat concerned about Steam being the only storefront that also combines with a Proton-compatible launcher. GoG could be a real competition if they added that option.