Background:
We have an AVS 2.0 environment running with many subnets/segments in Azure and need to migrate some VMs from the cloud back to an on-prem vcenter already connected via HCX. VM migrations work, but we would like to use HCX Network Extension to migrate these VMs on-prem by extending the network subnets/segments in AVS 2.0 to on-prem.

I tried to initiate network extension from the cloud, but at "Select source networks for extension to remote site" I am given: "! Network Extension should be initiated from <on-prem service mesh>" and I can only extend the network from the on-prem connector. I can create a network extension from on-prem to AVS 2.0, but that is not what we need. Need to select source network as the cloud network back to on-prem.

Is there a way to extend a cloud-based SDCC segment/network to on-prem using HCX? In my searching online I see it is "possible" but no examples other than on-prem->Cloud or Cloud->Cloud. 

Alternately looking at duplicating the AVS 2.0 network on-prem and bulk migrating the VMs and dealing with downtime after cutover, but NE would be preferable.