So if this is set to 20, and the registry key mentioned here is set to the default 7, will I still see 20 concurrent tasks?
That depends on a transport mode.
I'm having a hard time understanding what exactly this key does or how it effects multiple jobs running or disks being processed at once.
The registry constraint of 7 NFC connections is in power if and only if you use an NBD mode. In other words, no more than 7 disks can be backed up from a single host simultaneously when using nbd.
In proxy settings you configure the maximum amount of disks that proxy may take no matter which mode is used. For example:
NFC = 7, proxy task limit = 12, transport mode = hotadd - 12 disks can be processed at once
NFC = 3, proxy task limit = 5, transport mode = nbd - 3 disks can processed at once
NFC = 3, proxy task limit = 2, transport mdoe = nbd - 2 disks can processed at once
Hope this helps.
Thank you.