Unfortunately, I don’t know either. From my understanding, X11 as a whole is supported. Therefore, you should be able to hack your way through this. I suppose the installation instructions for Ubuntu should closely align to what’s required for Debian. So that’s your starting point.
Yes and no.
Has it got its own set of rules you’d have to learn and thus an accompanying learning
curvebump? Sure. Which, in actuality is mostly just knowing that Flatseal is your go-to whenever a flatpak causes issues.Is it a surefire method after you’ve become accustomed with it? Absolutely.
Besides, Flatpak is enabled by default on Linux Mint. The PCSX2 flatpak is even verified. So no additional setting up or whatsoever is required.
What makes you weary besides what’s already stated above?