When Out of Office is on and a backup user is assigned, the "Unable to Assign Task/Empty Role" notification does not forward to the backup user. It forwards to the original user who is OOO. This can cause the issue of a workflow becoming stuck due to a role being unassigned and the Backup not being notified to correct the issue.
Also, If a backup user is set and custom notifications are defined in a workflow the user must be a part of the role to get the custom notification, which may not apply to the back up user.
It would be beneficial if all notifications passed from the users to backup user no matter if custom or base notification.
Customer support service by UserEcho