I must be missing sumthin yet again....
The pedal on the Smart is not hung from above but rather it has downward leverage toward the floor of the car with an external bellcrank to the mastercylinder, etc... If you pull forward on a cable, like through the firewall, you would get very little brake pedal force ?
Do you have your cable coming up through the bottom of the floor and if so how do you connect to the pedal stalk?
This old saw seems a reasonable way to do a "surge" brake for sumthin like a little car, but in fact doesn't one get a lot of pulsing through the receiver from the rocking of the tow with variance in acceleration and such?
There are several supplemental brake systems that are indeed custom made for a given model of towed vehicle. The M&G folks make a very nice one that mounts behind the mastercylinder and provides proportional braking off the MH air or air/hydro system. An accumulator cylinder and lanyard provides for break-away brake activation. I like this system a bunch but have not seen one made for the Smart yet. I haven't checked with M&G as to applicability to Smart, and have only looked at them on mostly Jeep products where they perform very nicely.
I'm not all that concerned with normal proportional braking whilst towing a Smart due to it's light weight which is not equal to a pimple on my coach's butt, though a break-away system is ALWAYS a nice thing to have on anything yer towing. Stuff happens. I'm gonna have to take a look at the Nightshift break-away system and try to figure out how it is gonna work with our pedal design...
Real world experience is for sure a good thing to tap. Thanks for the info!