I also tried to get diriger games to install with heroic, lutfisk or whatever but never got it to work. Threw the installer to steam and it just works. Weird… So I just do everything through steam now instead of messing around.

Both of those things exist on Steam. If the Devs want to give access to different versions they can and many indie games do. And you can turn off updates in the settings for each game.

Edit: oof. I read badly, you already wrote that they can give access to different versions My bad for being a bad reader.