The host is running Proxmox, so I guess their kernel just works with it.
It does run the fan way more than I'd like, but its noise is drowned out by the original AMD cooler on the CPU anyway, but thanks for the info, I may look into it... But I guess I'd have to set up GPU pass-through on a VM just for that.
MMU units like the ERCF allow you to use a functionality called "endless spool", which detects spool run-outs and automatically switches to another spool in the same group.You still waste some filament, to be precise the length from the MMU unit inlet gates to the extruder, but whatever.