Got the TH back from the dealer today. They could have taken the ez path and remove 2 springs, matching most of the other units. But they did exactly what I wanted (but didn't request), they removed a single spring. Now the ramp lowers within about an inch of the ground without binding and little movement of the bumper. Should be fine as the springs age.
The tech also said the factory stated not to weld the bumper to the floor frame, that a small gap was needed for water drainage off the floor. Not sure I believe the reasoning as the bumper is about 3/4" lower, so water should drain easily off the sloped floor anyway.