I know some people use RM to reboot their hub nightly but this requires you to have hub security disabled. The only option I've seen with security disabled it to run something on an rpi. I built a small app that does it all self-contained to the hub (I really didn't want to setup an rpi just to reboot my hub!)
You can find the app here GitHub - dcmeglio/hubitat-rebooter it's pretty straight forward, specify the username/password to use to login to your hub and the time of day to reboot.
Hopefully the team will fix the underlying performance issues that have made this necessary but for me, after about a week, my hub is unusable.