I really only used it for syncing photos from my phone so I went to Syncthing. The NC web interface I found far too slow to be any use, so I just mount network shares over NFS.

And that is why I no longer run Nextcloud

RAID does not work today with any disks you may have: https://www.youtube.com/watch?v=l55GfAwa8RI

.The only sane option is ZFS with zRAID1/2.

An HBA with the SAS cables should run to about £50 used.