With Linux gaming clearly showing it's becoming more popular, and with GOG under new ownership, there's hope yet that GOG will improve their Linux support.
I think Steam, GOG and Epic have API/SDK that anyone can use. It is not like they check what every single person is doing. Steam has a problem with gambling and grey market trading that uses their services, it is not like they are actively going after them.
Btw, Comet main dev is one of the devs behind Heroic. It seems imLinguin is also based in Poland and very active with the GOG community. GOG definitely knows about them. Maybe something changes since they are willing to invest on Linux now.
I think Steam, GOG and Epic have API/SDK that anyone can use. It is not like they check what every single person is doing. Steam has a problem with gambling and grey market trading that uses their services, it is not like they are actively going after them.
Btw, Comet main dev is one of the devs behind Heroic. It seems imLinguin is also based in Poland and very active with the GOG community. GOG definitely knows about them. Maybe something changes since they are willing to invest on Linux now.