Yes, I thought of this too, but thought maybe there was a way of doing it without bringing the whole array offline.
On the main page for unassigned devices there is a button called "Add ISO File Share". This one requests an iso file according to pre-filled in text and only shows shares from the array, for some reason. Is there any way to have folders from the nvme to show up here? That would actually solve the problem.
The other button, "Add Remote SMB/NFS Share" only allows remote shares to be mounted, not local shares.
Maybe a feature request?