I'm not aware of an enclosure that has a problem running with open slots. I have a Synology unit that's running with 3/8 empty bays.
Data Hoarder
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
I am very pleased with my IB-3805-C31. A 5 bay USB (10Gbps) JBOD enclosure.
You access the drives as separate drives and can turn them on/off individually.
I use it with Linux and mergerfs and snapraid. Works very well. Silent and robust. Sabrent has an identical(?) enclosure.
Awesome, that was on the upper end of my budget but glad to hear it will work for my use case. Time to store some more 4k videos!
Thanks for your help.