The enclosure contains a special WD blue 4 TB HDD, which is not designed for continuous operation. As a cheap network drive on a router, I would use a WD red in an external housing. Or then just a real NAS for about 100 more.
I would never use it as an external hard drive on a NAS. Firstly, it will then run permanently again, and secondly, it has a proprietary USB3 connection; i.e. I cannot integrate it into the NAS as a RAID.
However, it is certainly suitable as a (manual) backup for a NAS that is connected when needed.

Same question here! Would like to use this external HDD on my Synology NAS and wonder if that works....