YOu are real need of Professional Services. Not a FREE forum.
Why don't you contact your "Draytek Routers" Rep, and see if he can help? YOu do have a relationship such as this with them, right? You are talking about up and down the country, so certainly you have developed that kind of relationship!!
I am afraid, you may be victim of the Peter Principle, and a free forum cannot save you from that!
It takes money to make money, and Free TYPICALLY COST MORE! Data loss, because your FREE solution has hacked the network, and taken control, and now you are stuck, along with the liability of your customers who EQ is also been compromised! Whew, free is not free anymore!