You can back up the object storage repositories with full, incremental, or synthetic full backups.
You can back up the metadata of object repositories with full and incremental backups.
From FR 11.23, by default, the Azure File Share backup backs up locked files using Azure file share snapshot . You can also choose to back up all files using Azure file share snapshot, see Backing Up All Files with Azure File Share Snapshot.
Note: You can back up the metadata at the folder level for Azure File Share.