Currently when creating a snapshot out of a backup, that backup is deleted immediately.

That doesn't make logical sense, and might violate the agreement for purchased backup service with the customer.

The backup should stay in the system for it's whole intended duration [4 weeks currently]

Making a snapshot should not delete the backup.

Making a snapshot and creating a duplicate droplet could mean wanting to troubleshoot things, before actually restoring anything live.

Let the backups we paid for stay until their time is up.