It's a great question, I have no idea how this works in the cloud but I am trying to start some conversation here. I am using generic term 'database' here instead of specific oracle plugin. Hopefully, NetApp Cloud Gurus will chip in.
Considering the database Backups (Application consistent) : It has to be consistent volume block level. So, the primary backup has to be on either on-premise ONTAP system or CLOUD EC2/EBS/CVO (Primary Backup) and then perhaps you can vault the 'application consistent volume level' snapshot to Object-storage/S3 (Secondary Copy). I am guessing, this seems straightforward and should be doable with Snap Center. When it comes to restore, obviously depends upon the how far back you are restoring from i.e either Primary EBS/CVO or secondary S3. I am guessing, if the files/data is needed from the S3 backup, then it must be restored to the Primary(Premise/CLOUD) and then bring the db up. Just as we use to do with normal vaulted backups, just my thoughts....
Something related I found: (Hope it makes sense)
https://cloud.netapp.com/blog/perform-database-backups-in-the-cloud-with-snapcenter
https://docs.netapp.com/us-en/occm/task_restore_backups.html#restoring-a-volume-from-a-backup-file