Pre-set, pendulum (inertia) and surge brake controls are WAY more dangerous than a pressure based brake system like Max-Brake (Ford TBC) and other previous ilks.
Why? Those systems that do not rely on towing vehicle brake pressure are almost NEVER providing the "required" braking on the trailer - either too much or too little, never the right amount.
On a damp road the trailer brakes skid causing loss of control. On a dry road, they don't produce the required braking, especially under hard brake events. This causes the trailer to push the tow vehicle and is VERY dangerous.
With a brake pressure based system, the trailer brakes are set once so the controller knows how many amps the trailer needs based on the pressure applied in the tow vehicle system. As the pressure increases or decreases so does the trailer brake force. If you very gently apply the brakes (as in wet or snow) to retain control, you get very gentle trailer braking, exactly what you need.
In a surge system, if you are on ice or snow you get ZERO trailer braking! The trailer shoves you right thru the intersection. Such systems should be outlawed!