Exporting across a WAN link may work, but it not optimal and may have some unexpected consequences.
The initial export across the WAN link could take several days to accomplish. During this time, any interruption of the export will result in the exported VM being deleted and the export must be restarted from the beginning.
This is not a bug; this is by design. AppAssure exports data directly to the disks of the VM. If the export is interrupted, the disks are left in an inconsistent state. There is no recovery for this, so the export is restarted.
If you are using this solution for virtual standby, your DR VM could be gone for several days until it reexports.
So - bottom line - Exporting across a WAN may work, but it is neither optimal nor a supprted method of export.
Install an AppAssure Core as a replication partner to the original Core. Replicate the agents that you wish to export to this new core. Then, have the new target core perform the virtual standby local at the DR site.
In the event of a failed export, the VM will still need to be re-exported. However, the recovery points from which the export is created are now local to the hypervisor so the entire VM does not have to be sent across the WAN.