|which in effect reacts to sudden impacts like a pot hole and opens a second valve to cushion the ride.
When a pot hole forces the shock piston to move rapidly, this second valve opens to evacuate oil from the inner tube faster; which in turn allows the spring to soak up more of the impact forces instead leaving the dampener to deal with it by transmitting harshness through the suspension hard points onto the chassis and into the cabin.
It sounds like its dual valving; one for quick pot holes, another to keep the car from rolling or pitching on high speed curves.
Koni has a similar system called Frequency Selective Dampening wherein based on the frequency of the piston movement a second valve will open. Low frequency movements are connected to body control, and high frequency is directly related to axle input
This 'active tech' as they call it, "controls large body motions and cornering forces but smooths expansion joints and rough roads for improved comfort."
Unfortunately, I don't think Koni makes a Z32 fitment for this type of shock... BMW gets all the good stuff.