Got my trailer brakes to work smoother, seems the cable to my Jordan Ultima was set too tight. Whenever I would lightly hit the truck brakes the trailer brakes used to be very agressive and overly sensitive. The reason was that the pedal in my truck actually travels for an inch or so before the vehicle brakes start to work, energizing the trailer brakes too soon, out of sync, normal I guess? Put a little slack in the cable and now it stops much smoother. I guess this is called the "gain" adjustment in your typical controller?
(c'man, hope you can get your brakes straightened out)