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the "surge" described has no correlation to the throttle position.
the fuel pump may make pressure pulsations as it turns but the real culprit that the dampener tries to solve for is the water-hammer effect inside the fuel rail when the injectors open/close. imagine a tube full of liquid, at 45 psi, with 4 outlet valves that open and shut in milliseconds. that liquid in the tube wants to rush out the valves and starts moving but when the valves shut the fluid crashes against the closed valve and bounces around - this is the pressure spike inside the rail.
the dampener is a spring-loaded chamber that can expand slightly and quickly to absorb that pressure spike (since the fluid, fuel, is incompressible). this repeats a bajillion times a second (or whatever the injector open/close frequency actually is).
it helps keep the fueling more stable but is largely a NVH reducer. lots of cars with the same Bosch fuel injection in the 70s-90s did not use dampeners and were fine. and dampeners largely disappeared with the introduction of sequential fuel injection since only 1 injector was firing at a time. however some more luxury-oriented cars with sequential injection have since added back a dampener for the NVH reason mentioned above.
i have a non-Porsche engine in my car using the stock fuel pump, batch injection, and no dampener, and it runs fine but there is some taptaptaptap noise audible which i attribute to the injectors.
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