Softening or stiffening the high speed stack changes the damping force everywhere, not just at high speed.
The example below from the MXScandinavia thread on Thumper Talk replaces the 0.2 mm shims in the stack taper with stiffer 0.25 mm shims.
The dyno test results (data points) show the shim stack is stiffer everywhere across the speed range, not just at high speed. Shim ReStackor calculations (shown by the lines) shows the same thing. High speed damping can be stiffened by tuning the crossover or softened using a preloading ring-shim (linky, fundamentals).
