Joplin requires you to migrate each notebook individually so it's fiddly if you have lots of notebooks in lots of folders.
But one you've done it you're free!
Well worth the effort. I downgraded to free Evernote after the last price hike and stopped using it... Now I can delete the app entirely.
I found that the following helped: by never turning it off it just continues where it left off last time it was used. This assumes power is independent of TV.
Useful Settings This ADB command kills the sleep timer:
adb shell settings put secure sleep_timeout 0 and this ADB command kills the screensaver:
adb shell settings put system screen_off_timeout 2147460000