I am currently trying to make a server attached to a GL-150 accessible via the IP acquired via VPN. Its an OpenVPN connection and the requests are reaching the router (I can call up the web interface etc.), but apparently the router does not forward it to the attached device.
In the above summary, they talk about the ‘OpenVPN Access Server’ and the server being accessed is at that site. But, you could think of the openvpn devices at each site as being an ‘OpenVPN Access Server’ and having servers behind them.
Another option would just be to run OpenVPN on your server and then it will have its own VPN IP that can be accessed directly. But, there may be reasons you don’t want to do that.