Epic is kind of a thorn in the side for me when gaming (on a Linux distribution). There are a few Epic exclusive games that I'd like to play (Arise: a simple story, Journey, etc.), but they don't even have entries in protondb.
That's probably due to Epic not having a launcher for Linux. A few months ago(?), I read it had become possible to run the launcher through Wine, but I don't think that's changed anything on the porting side.
I worry that games which are released as Epic exclusives may fall by the wayside when/if they eventually become nonexclusive.