This is just like the StepSaver from BOP, the Gravely Sulkys and Jungle Jim Sulkys. It does "trailer" behind the unit but the pivot point is right in front of the standing platform not up on the mounting point of the entire sulky to the mower. If you were to stand pigeon toed on the platform with your toes touching right at the pivot point your toes would always be in the same position regardless of where your heals are at.
With that being said the pivot point is a few inches further than I would like to see. Ideally you would want the pivot point that lets the platform twist/turn to be right at the front of the standing platform. Also the extensive use of washers to provide the adjustment in how far the platform is from the controls concerns me. K.I.S.S. And multiple washers is not that.
I like the idea of a "cushioning" sulky but I find more trouble in the vibration that comes through the handle bars of the mower itself rather than what comes through my legs. Thats why I have knees.
Would like to see a mower produced that has some sort of suspension system for the control bars.