Elephant Racing has a great site for suspension information and procedures.
I am not sure the shock "Bounce test" is sufficient to measure the proformance of the front shocks. It might work on a typical car or truck, but iffy on the Porsche.
My "other thoughts" would be to check the motor mounts if you are checking all the rubber.
Even if you do not have any symptoms of typical failure like vibration issues or leaking fluid, you should check the "height" of the installed MM. Porsche spec is 62mm minimum base to base installed.
GL
John