I didn't know that, thanks for that lesson.
Not sure which part but glad to inform. For a valve to 'close faster' one would...need to cut the dwell and power. Most airguns gun that are loud relative to their power are generally exhibiting hammer bounce, air escaping somewhere other than the bore, or an over-driven valve remaining open beyond the point that air can transfer meaningful energy to the projectile, thus becomes energy escaping the bore creating more noise.
You have to deliberately take steps to create a 'blow open valve' or a slow closing valve that remains open until pellet leaves the barrel or the air going into the barrel is no longer useful, by either over driving the valve or arranging such that there is no, or next to no closing force present at all. Hammer bounce naturally occurs unless mitigation is present, due to the nature of how rapidly valve closure nominally occurs, sending the hammer back violently into the hammer spring to rebound and re-open the poppet before the regulator even gets a chance to completely refresh the plenum.
I've been hearing it for the last 8 years, light hammers, this valve tech, that valve tech making for snappier shot cycles. Well...I have one of the lightest hammers (4 gram hammer) and best valve techs (pilot valve) available in my gun, and its no more efficient nor making more any more power than it was conventionally. It simply requires less force to operate, and a lot of complexities to produce. The only aspect of it that is snappier is the overall hammer lock time, in my case.
*edit*
And for a valve to make more power than another valve in the same setup in the absence of valve lock or valve dwell limitation, the 'tech' would have to extract more power out of air than what we currently are, by super heating the air or something to that nature, which technically is raising the pressure. And before someone mentions axial valves, that's reclaiming energy loss due to two less 90 degree turn, which isn't ground breaking and the industry isn't heading that direction.
-Matt