I had an unscheduled adventure last week with the Prodigy which may be of potential interest to other Prodigy owners. After hitching, the .c. display on the controller looked normal and the manual brake lever actuated the trailer brakes with the expected voltage.
But the trailer was feeling noticeably heavy on the stops. After driving 30 miles or so, I was checking things, and found that the connector at the back of the Prodigy wasn't plugged all the way in. I hadn't noticed, but the .c. display had not been changing to voltage numbers when applying the brake.
This situation was the same as if the signal from the brake pedal was not connected. The trailer brakes were not actuating because the controller wasn't being told I was braking. Now there's one more important check to make after hitching up: "Do you get numbers on the Prodigy when you step on the brake?"
And now that I have some practice driving without trailer brakes, I can speak from experience in not recommending it.