Yes, and you might want to ask in the datahoarders community.
While I dont use a mini-pc, I have a server with 48TB in it on spinning disks, and I've built a hybrid DAS/NAS that I back up to.
I use this 4-bay DAS: https://www.amazon.com/gp/aw/d/B078YQHWYW I chose it because it supports USB 3.2 Gen 2 and I've been pretty happy with it.
It's usually plugged into my server directly, and I use ZFS to snapshot and send to it. However, I also can plug it into a Pi5 and use ZFS send over SSH to treat it like a NAS. The Pi can of course run Samba/CIFS and SSH for sshfs.
The biggest downside to this structure is probably the metadata speeds for ZFS over USB (looking up snapshot names), but you could always use a cache drive with ZFS.
I highly, highly recommend ZFS and figuring out your software requirements before picking hardware.
Happy to answer any specific questions, too.