I have tried to address this to Asustor, but they said that then they would not sell their own nas servers, but what i miss in my nas system is an app that my Raspberry pi 2 b with OpenMediaVault can connect to like a remote control, but not like VPN connection, because it must use its own internet connection and not mine.
All i can refer to is http://developer.asustor.com/ and hope someone can see the idea in this.. the plan is to have many small "drones" connected to my main nas and Raspberry pi 2 with OMV seems to be a very good drone (No noise, No fan, Low power usage, can handle a 100 Mbit local network which is fine enough and its cheap compared to another nas and there i would still end up with the same issue.