@kev Tangential, but relevant: I used to have Cloud Sync do off-site backups to Backblaze. The problem was that for some reason or another, Cloud Sync would stop working and there was no way for it to notify me of failures. So I would go for months with no backups before discovering the problem.
I solved the backup monitoring problem by using a Raspberry Pi, because I couldn't find any option that would work on the Synology device itself. So now I have to manage another Linux box anyway :/
@pcrock I backup using cloud sync in the exact same way. I login to my syno a few times a week for various things, so if something has failed, I’ll see a notification. Although I’ve never know it to fail.