vCAC Windows Deployment Stuck at CustomizeOS State

I am trying to add domain admin account to the local administrator on vCAC provisioned Virtual Machine, however, when i try to deploy with the below property values the VM provisioning gets stuck @ Customize OS and finally fails.

Property Value:

VirtualMachine.Admin.UseGuestAgent true

VirtualMachine.Customize.WaitComplete true

VirtualMachine.Software0.Name     addusertoadmin.cmd

VirtualMachine.Software0.ScriptPath c:\scripts\addusertoadmin.cmd {Owner}

Script @ VM:

net localgroup Administrators %1 /add

Will the VRM agent contact IaaS server while initiating above customization? Since the subnet that vCAC IaaS server is different than Provisioned VM and these 2 subnets dont talk to each other.

Thanks