to explain the use case here.
we have no desktop PCs in the house at all. it's either laptops or mobile devices.
the only "desktop" system is the windows 10 pro "server" which is in Intel NUC running in headless mode. it runs Plex, Radarr, Sonarr, Sabnzbd, Transmission, Jackett, and numerous other services. as it's a NUC there is zero internal space, and i like it that way.
the primary purpose of the server is to serve media content to the various plex clients.
building another PC is not an option i'd want to go down. it would either be NAS or more USB external drives.
also, FreeNAS is not something i'd ever want to use. i'm sure it's pretty good and once you know it inside out it works a treat, but i've also heard (and seen) some horror stories with it too - not my bag and not something i want to get involved in.