Could you either:
1. Add a OpenVPN Client and gui to the AS, for use as a remote Site-to-Site option?
2. A standalone Site-to-Site Client download.
3. Maybe a VM appliance for this client.
Be bought OpenVPNAS, and the setup was easy.
But setting up the openVPN open source client as a site-to-Site VPN was much harder than it should be. (it was even hard to figure out what to download
)As for option 1, I can see that making it potentially easier for a future Mesh type deployment.