backup scheduling

I have a question about the 'Repeat missed' feature for scheduled backups in Proxmox: We have backup jobs scheduled to two different destinations. I understand that Proxmox runs only one backup job at a time. If the backup to destination 1 is running, the job to destination 2 will be skipped...

I recently just sat up PBS, although I'm a long-time VE user. I am attempting to setup a scheduled backup to a tape library for archival purposes. The issue I am running into is that I don't see the option in the drop-down list for the Job's schedule for the particular use case I'm trying to...