I’m replying here at the top of the thread again because it’s getting pretty crowded down there. I got steam installed and it’s working. I ran Baldur’s Gate 3, which worked flawlessly on my Pop install with Gnome, but in KDE Plasma on Arch the screen is going black for about 10 seconds at a time, then the game shows for about 5 seconds, and it goes black again. Is that the flicker issue you were talking about? It’s a pretty bad issue. I’ve been unable to resolve it so far. I’m pretty burned out working on it for now, so I’m going to take a break. But I wanted to see if that describes the flicker you were talking about or if I’m experiencing something different.
Edit: I disabled screen tearing in the KDE options and it stopped. I also made some changes to my config files, so I probably should have tested without disabling screen tearing first, but at least it’s fixed! Sweet! I have a working Arch Linux gaming setup now.