I always set them in BIOS to "FULL ON after Power Back", it also ensures that after a blackout the miner will turn on. Then I also enable WOL and Power On by RTC alarma and set it to something like "everyday 12:00:00 PM", so I don't need to come close to the room with miners, even if for some reason they turn off, they will be back somehow.

This way I can go on business trips for whatever long I want and I don't need to worry about miners going down (except for PSU failure, but that's different story).