I don’t have the answer to your question, but I’m curious why you want to install ROCK? I’m presuming your Roon Core works with your current Linux system. I doubt if there’s a performance improvement to be had and you take a risk trying to run ROCK on a non-supported system. It’ll probably work, but you’ll get little support from Roon if it doesn’t or if something goes wrong.
The question is what you are expecting from such a system? If you mainly want to run roon on a ROCK, you could leave music files on your Linux machine and create an access for the ROCK via network.
If I had a library of 14TB (and I have some TB more than that) running on probably outdated 4TB magnetic discs, I would be more concerned about reliability and redundancy in case one drive fails. So moving the collection to a NAS with RAID1, mirroring and automated backups would appear to be a safer solution than moving to a ROCK machine. Depending on the size of your library in terms of tracks, you might even want to choose a NAS which is powerful enough to run roon locally (there are some very nice semi-pro QNAPs for that particular case).
My current setup is Roon Core runs on a linux Debian machine and a Mac Mini as end point running Roon Bridge. My initial idea was to combine these into one simple device, simple meaning low maintenance.
My library hasn’t change in years, but I keep a copy on another set of disks in case of disk failure. I do listen to Tidal but don’t buy albums. The four 4 TB disks are all 2.5" due to space limitation in the fanless case.
Now that I learn’t more about ROCK and the NUC platform (I wasn’t previously aware of the 1 internal disk limitation). I think ROCK is not for me.
I’ll look at the big NAS running Roon Core option, but budget is limited.