@CodeMercenary I use the paid for XOA and it backups up its config to the cloud so it wouldn't be a problem for me to restore. You can easily set something like that up by backing up to a store location then having that backup to a cloud storage location.
As far as having the XO instances running Im not sure how that would work. I know with NBD storage you should be able to connect to the hard drive with multiple XO's (I think) but the problem I ran into quickly was the fact that when I made a backup using my XOA, the XO from source would see it as a backup without an associated job. If you had three XO's running with 3 different remote storage locations I don't think you'd have a problem with that. Instead you might run into the XO's seeing the 3 different backup jobs running , 2 of which, they don't know about.
I use XOA to backup to a different storage array, then I have that storage backup to the cloud. My backups aren't really up to "standard" but thats all I can do for now. My plan is to make backups to a different storage pool on the same central storage I run my VM's on, back that whole unit up to an off site unit with ZFS replication, then back that backup to the cloud with StorJ. Right now Ive just got the one backup on the same Storage server and the StorJ.