To create or update a feed through a batch:
The jobs should be in the Waiting for Delivery status.
There might be a small delay between QC Approving all jobs and the Deliver button becoming available.
Do not individually deliver your jobs as they will not be used to update the master feed file.
The Post Delivery Workflow also creates backup files for the master feed file. The backup files do not serve any purpose in the logic of the feed functionality (deleting them has no impact on the feed functionality).
Their purpose is to offer operators a mechanism to manually restore previous data for the master feed file. The Post Delivery Workflow automatically creates and delivers both the master feed file and the backups to the configured destination.
There is no direct relation between the Post Delivery Workflow and the location of the master feed file. If the master feed file is delivered into external buckets, outside of the organization bucket, the master feed file will not discoverable in the Media Items list of the organization.