I tried it with @plasmamobile#PlasmaMobile first and while I absolutely loved it, I still had frequent crashes.
Turns out, the regular #KDE#Plasma desktop works flawlessly! On an almost eight year old Android Tablet! I couldn't believe it.
I just wish there was a better on-screen keyboard. Which is weird, because the login screen comes with a perfectly good "qt5virtualkeyboard" but I can't use it anywhere else.