We built an enclosure fort our printers from a metal storage rack & added active ventilation that suck out any fumes outside the building. Still, you need to physically get there, check the bed is clean & start the print manually.

There are are also regular software checks for overheating or thermistor wiring failing & we know they are there and are enabled as we built the Marlin firmware ourself from source (which is quite easy once you properly configure it). Not to mention we are sure we are the ones in control over the firmware.

We also have a bunch of web cameras watching the printers print that we can monitor remotely.

The main board of my 3D printer short-circuited and caught fire once. I don't know what would have happened if I wasn't around, but I'm not leaving my printer running on its own without supervision.