If a quick release isn't properly seated and locked, bar will get destroyed if you put any compressive load on them. They should not fail even if put under full force of the vehicle, but again that is not what they are designed to have happened on a regular basis. There is a massive difference between a system designed to handle these loads regularly and safely vs a system that should be able to handle it in an emergency situation. A surge system would never reach the loads you are stating if it was working properly. The brakes are triggered before the spring/damper is fully compressed and it slams metal on metal. During that time, the only forward load on the RV is the spring/damper force.No, the bar isn't going to fail ever unless it is overloading, or the towing vehicle gets in an accident. And the electric brakes fail all the time. That is why I went with a mechanical system which requires compression before the toad brake is applied.
AND if a propulsion system was put in place it makes your surge braking impossible.