<font color="blue"> The second modification was to the reverse treadle. Reverse throws your weight forward, pushing your foot down harder on the reverse pedal. This is even worse on rough terrain (the only kind we've got). Even after some hours of operation, I still had a lot of trouble backing smoothly.
Since backing at full speed in a lot of spots on my property should probably be preceded by a suicide note, I decided to limit the travel of the reverse pedal. I took out one of the bolts above the right pedal and replaced it with a longer one and a double locking nut. This let me adjust the maximum reverse pedal travel to a safe amount.
I wasn't really happy with the double compression springs provided by PT, so I got dethatcher springs from the mower parts section at Lowe's. I reversed the bend on the end of one and mounted it to make contact in the first few degrees of reverse pedal travel. It doesn't quite touch in the neutral position.
With those modifications, reverse is safe and controllable for us.</font>