Первая же ссылка из гугля утверждает, что The scale-out backup repository functionality is available in the Enterprise and Enterprise Plus editions of Veeam Backup & Replication.
• If you use Enterprise Edition of Veeam Backup & Replication, you can create 2 scale-out backup repositories.
For each scale-out backup repository, you can add 1 object storage repository and 4 extents: 3 active, and 1 inactive (that is put to the Maintenance mode). You can add inactive extents, for example, if any of active extents has no free space, and you want to evacuate backup data from it.
If you add 4 extents and do not put any of them to the Maintenance mode, the jobs targeted at the scale-out backup repository will fail.
Enterprise Plus Edition has no limitations on the number of scale-out backup repositories or extents.