@nprofile1q... I really wonder what's going on here. I played StarCraft (original version) fine even in Lutris some time ago. It shouldn't have any such glitches with Heroic. (I also use the flatpak version, but I guess I haven't updated in a week or so.) What is the glitch?
BTW if you use ProtonUp-QT you can not only update the main Proton-GE that Heroic uses, but you can add other versions. There is a CatchyOS version that is a bit bleeding edge so normally I would only recommend it for very recent games that don't work right on the normal Proton version, but you could also see what happens with that. Just install a different version, then click the settings on the game (the three lines with dots on them,) and change to another one to try a different one.
BTW if you use ProtonUp-QT you can not only update the main Proton-GE that Heroic uses, but you can add other versions. There is a CatchyOS version that is a bit bleeding edge so normally I would only recommend it for very recent games that don't work right on the normal Proton version, but you could also see what happens with that. Just install a different version, then click the settings on the game (the three lines with dots on them,) and change to another one to try a different one.