Internally, I know that the velocities are not reaching their maximum because of the sound of the patches. For example, if I have the basic 0-0 ConcertGrand patch loaded, and I send midi information from my DAW at velocity 127, I know how the piano sounds at that velocity level. It is not possible to create the same brighter sound from playing the PX keyboard. UNLESS I go into the system settings / general / touch and set that to 'off', then set the 'touch off velocity' to 127. Then every key I play will be at 127 and the patch sounds with the maximum velocity. When setting the touch back to light, normal or heavy, it is impossible to create the maximum 127 velocity sound on the patches.
That's how I know that the velocities are not reaching their maximum values for the internal sounds as well as t the MIDI output. I wonder if it's possible that something is wrong with my particular PX? I bought it about 4 years ago, and I think it's always been this way. I just didn't really notice until recently when I was trying to play the sounds from my Yamaha Reface CP. It's impossible to get the 'bite' out of the Rhodes and Wurli sounds on it, which are quite nice. They sound very mellow when controlled from the PX because of the velocity issue.