https://docs.opsmanager.mongodb.com/current/reference/configuration/#Backup-Versions-Auto-Download

Set this to false only if Ops Manager does not use Automation and the Backup Daemons do not have internet access. If you set this to false, an Ops Manager admin must place the MongoDB binaries on the Backup Daemon servers.

I can't imagine anyone would actually need to set this to false, but if they do, they need the extra instructions here: https://docs.opsmanager.mongodb.com/v1.8/reference/configuration/#mongodb.release.directory
In particular, they need to be told the binaries need to be uncompressed. (Which means they'll need a compressed version for automation, and an uncompressed version for backup)

https://docs.opsmanager.mongodb.com/current/reference/configuration/#Backup-Versions-Auto-Download-Enterprise-Builds

Corresponds to configuration file setting: mongodb.release.directory

Nope. I don't think we ever had a configuration file setting for this.