I'm guessing it's about the rm -rf /etc/iscsi/send_targets/initiator/. In my case tis is far from empty.
In my experience there is no need for step 3) and 4) but you do need to do 1) and 2) on all nodes.
FWIW, you could also add some tooling that uses the Proxmox Backup Server periodically saves the list of created backups in some directory, or database of your own.
Even using the debug tooling we provide could be enough, e.g...