Correct me if I am wrong, there is truly no such thing as an emergency brake on a car/ truck. The term is used interchangeably with parking brake.
I believe what most states require is a parking brake of some sort that can be used in the event of an emergency to safely and controllably bring the vehicle to a stop as well as hold the vehicle at rest. This necessitates a system that is independent of the vehicles hydraulic brake system, therefore line locks and mico-locks can't be used. Inaddition, I don't believe the factory calipers where designed to hold that type of line pressure for extended periods of time.
In that case, wouldn't a driveline brake suffice? It applies pressure in a controlled manner?
I've been looking at the E-Stopp to see if it has a greater range of motion over the stock pedal set-up as I haven't been able to find a ratcheting style pedal assembly that I can retrofit. I believe the E-Stopp has already been approved for Parking/ Emergency brakes. I just don't know anyone that has one.