I have used a Brake Buddy Classic on numerous toads and never had a problem. It is essentially the same as a surge brake using an inertia switch and a small compressor as compared to a cable. On the Brake Buddy you can adjust the sensitivity to avoid activation just from the exhaust brake. I would imagine either on the tow bar or through the cable tension you can adjust sensitivity.
My doubles trailer had surge brakes with no adjustment and long down hill grades the brakes would get warm unless I stopped and locked them out.