Alternatively, you can simply set up an rsync job yourself (which is really all it did) in
/etc/sympl/pre-backup.dand/etc/sympl/post-backup.d.
Can you elaborate on this a little for me 
I wish to rsync to my NAS drive at home. I’ve already sorted out the authorization keys so it does not need a password.
Do I just need to create a file such as “02-pre-rsync” in /etc/sympl/backup.d/pre-backup.d/ containing
rsync -azP --delete username@server:/path/ /var/backups/localhost
This will make sure the local backup matches the remote backup. (although I’m not quite sure why this is necessary?)
and a file such as “02-post-rsync” in /etc/sympl/backup.d/post-backup.d/ containing
rsync -azP --exclude '*.lock' --delete /var/backups/ username@server:/path
This will sync the latest backup to the remote server