at least i went on a successful side quest after i noticed that the raspberry pi that powers our monitoring TVs froze because of the heat (it's been in that state for a long time apparently, just no one fixed it)
did some researching and now i've enabled the watchdog timer, so if the timer doesn't get reset by systemd for 10 seconds the thing resets and hopefully springs back to life
Create /etc/systemd/system.conf.d/watchdog.conf with
[Manager]
RuntimeWatchdogSec=10s
(This sets the timer to 10s, and makes systemctl reset it every 5 seconds. Don't set it too high or it'll fail to reset the timer, with a restart loop as a result)
