I’ve been running ROCK on a NUC8i7BEH for 4 years, and it’s been a dream. Hardly ever have to reboot it, and it’s never failed after an update or the occasional BIOS update. Until last night 
I updated the BIOS to the latest revision (90), and the NUC was unable to find a boot drive. Looked in the BIOS which showed the correct boot drive as having priority, and legacy boot was still active, but the NUC would not boot. After 30 minutes of trying various things, I realized that the only way out was to install a fresh copy of Roon OS. I was not a happy camper.
Long story short, I changed the NUC to UEFI boot, flashed the new image, installed the OS, restored a fresh backup, and was up and running on the “new” core, including an OS update, in less than 15 minutes. The process was simple and went as expected.
Very impressed with Roon’s ability to recover all settings as well as library entries in the restore process, They saved me from myself. THANKS ROON!