if what you are saying is accurate, reducing the hammer blow distance by raising the rest rail would increase the lost motion of the key, so you lose velocity given THE SAME input of strength, HOWEVER, theoretically, since you can still apply ape-strength, even with lost motion, you can achieve the SAME PEAK velocity for the hammer.
there might be a corner case, where a child could not acheive peak with the pedal depressed, but there's no question an adult could.
so in your simulation, you would make it more concaved a response, reduce from ppp to ff, down whatever steps you feel is appropriate.
Again, this is under the assumption that your description of the mechanism reducing hammer blow distance is accurate.
