This is how I finally gave in to using FlatPak. I wanted Okular, but also wanted the rest of the QT stuff it's own little sandbox as I wasn't using it anywhere else.

I did the AppImage thing for a while, but it was too difficult to keep up to date without the developers prodiving that themselves.

Side Note: Flatpak is actually pretty nice, the lengthas I went to avoid it were pretty unreasonable in retrospect.