You can always use the forum search. Example: Search results for 'OWC' - Roon Labs Community
You need RoonOS (Nucleus / ROCK) build 261 production or newer if you run Roon OS on your NUC (and of course a NUC with a Thunderbolt connector) to even have some Thunderbolt support. It is unclear if Roon OS can fully support your desired DAS.
NOTE: The OWC DAS’s are AFAIK designed for Apple MAC. Using it with anything else is at your own risk and without guaranteed success or support from OWC. IDK if anyone can tell if an OWC DAS with RAID will work on Linux, let alone a minimalistic Roon OS. Roon OS also offers no way to format external storage, Apple stuff usually comes with an Apple FS of some sorts and Roon OS likely has read support only for Apple FS’s (at best).
If you really want to use third-party Apple accessory products, better stay with Apple – buy a suitable Mac Mini for example as your machine for Roon Server.
Reread also:
PS: I can still not see a good reason for using a big, multi-drive DAS for a library that fits a single drive.
Why assuming anything? Does OWC not provide manuals and support for customers that can be used to answer such questions. Maybe there is even a user forum for OWC owners?