One thing I have found with my S-2A is that the rudder pedals in the rear cockpit are fairly short. The pedal itself is about the same length as an S-1 pedal but the S-2 heel tray puts your foot higher on the pedal. I'm not sure why that was done but for me, trying to stay off the brakes, it is less than ideal. So, I have done some design work to move the heel tray down which should put the ball of my foot around the top of the rudder pedal instead of in the middle of the brake pedal. This will require making new rear trays but it will be completely reversible by re-installing the original trays.
One other thing that will be happening while the airplane is exposed for the annual is nutplates for the trays. It is a ridiculous PITA to remove and replace those trays because every screw has a nut that needs to be dealt with. No more of that chore thank you very much!
Here's what I have come up with;

This is the standard heel tray. It sits above the pivot tube of the rudder pedal which effectively makes the pedal shorter.

This is my new tray design. It sits below the pivot tube and lowers the pilot's foot about 1-3/16". This will keep my leg a little lower too which is good for staying farther away from the passenger and their belts. The front screws are shared with the front tray's rear screws. If the outboard edge of the new tray needs additional support I could add a clamp to the vertical tube but I hope that's not necessary.
One other thing that will be happening while the airplane is exposed for the annual is nutplates for the trays. It is a ridiculous PITA to remove and replace those trays because every screw has a nut that needs to be dealt with. No more of that chore thank you very much!
Here's what I have come up with;

This is the standard heel tray. It sits above the pivot tube of the rudder pedal which effectively makes the pedal shorter.

This is my new tray design. It sits below the pivot tube and lowers the pilot's foot about 1-3/16". This will keep my leg a little lower too which is good for staying farther away from the passenger and their belts. The front screws are shared with the front tray's rear screws. If the outboard edge of the new tray needs additional support I could add a clamp to the vertical tube but I hope that's not necessary.