Innovation?

I am responding with an 8-year delay!!! It seems to me you are talking about the fourth pedal of Fazioli (Italian!). It allows the action to be tilted in a way that decreases the key dip and the distance of the hammer from the string, leaving its proportion unchanged. This allows playing pp without altering the sound since the hammer always hits three strings but with less energy.

Here is my take: if it had been a great innovation, it would have made more "noise" and today it would be very widespread. I assure you that with the right regulation and with the perfect restoration of the correct friction values, it is entirely possible to play the most extreme pianissimo without having to help yourself with the "1 string" pedal (which modifies the timbre and can also be used to play loudly) and without sitting there searching for it with such mental (and physical) effort that you go crazy! I say this from experience: if well tuned, even a quarter-pedal, despite its limits, can handle the most extreme dynamics with the maximum required relaxation and without strange aids.