I was referring to cloud backup clients integrated into the NAS itself. As you noted, very few cloud providers allow backup of networked shares, either directly or mapped. Some allow attached drives to be backed up.
Ah sorry.
I think I would be happy enough going with a client on a machine on the network but I'm not sure now.
Are there any specific advantages of having the client residing on the NAS only other than not having to have a local machine running all the time?