Hi,
The backup is only used to initialize the staging server which is setup as a slave of the production MySQL Server. The staging server stays up to date with production using MySQL replication.
Once the staging server is initialized, you can setup a SYNC policy, to generate subsequent snapshots, based on a schedule, which uses the staging server. No other backups are required, unless the staging server runs into errors or is not able to keep up with the production MySQL Server
I hope this helps, do let us know if you have more questions.