Yes, you can set the NUC10 to Legacy Mode–I’m trying to remember the settings changes I made (found them here in the Roon Community) so I may have to reset the unit, look in the bios, and then add to this message. UEFI mode will not work.
And my fan is nearly silent–I don’t hear a thing.
UPDATE: The answer wasn’t in the Roon Community, it was on an Intel forum. Here’s a link to the info. In short, you need to disable both Secure Boot and Modern Standby. Then you can enable Legacy Boot.