Forest Recovery Project warnings (4331292)

It is highly recommended to use a local user account instead of domain credentials to access the backup

The warning was added in 8.7.1 as a feature to outline that if storing backups on a remote host (not the DC) then it is a good idea to use a local account on the remote host instead of a domain account. In the event of a domain/forest outage, its possible that the forest recovery agent will not be able to authenticate to a remote storage location to retrieve the backup using domain credentials. 

It is best to use a local account on the remote host or even better, store the backup on the domain controller.