With this ticket: https://jira.ixsystems.com/browse/NAS-109762 sharing raw disks via iscsi removed from SCALE.
The tooltip in the extent section of the iscsi sharing section has incorrect verbiage that needs to be changed.
The tooltip should remove the references to "unformatted disk" and "controller". It will only show unused zvols or zvol snapshots.
I'm sure there are also other references in documentation and such so those will need to be checked too.