An inertia-activated controller has no way to sense brake pedal pressure.
Correct, neither does the Maxbrake/Brakesmart, your point?
If the tow vehicle is capable of slowing the trailer (creating deceleration) without trailer braking the tow vehicle's brakes will swing the pendulum and initiate trailer braking.
If a tow vehicle isn't capable of slowing the trailer it shouldn't be on the road! (with or without a trailer)
You have a lot of learning to do. The BrakeSmart and MaxBrake DO sense hydraulic line pressure directly. Both of them use a small pressure sensor (transducer) which is inserted in the brake line directly off the master cylinder. When the brake pedal is pressed the sensor senses hydraulic line pressure and produces a proportionate electrical signal to a mini-computer which amplifies the tiny microvolt signal and produces brake output.
I stand by my original statement. A Dodge Ram is NOT capable of stopping a heavy fifth wheel trailer without trailer brakes in a reasonable distance and certainly not capable of making a panic stop. The most you can hope for is a long delayed stop over excessive distance.
People who have never used a real brake controller, a BrakeSmart or MaxBrake, often defend the useless inertia-activated controllers. Anyone who has used both knows better.
You are certainly free to use a Tekonsha if you like it. I wouldn't use one for a paper weight.