First of all ... holy moly i played around with the kemper fuzz and it is amazing i tried to recreate my fuzz pedals and it komplete delivers ...
Kemper did an amazing job with it imo, i love it!
There is only one thing that would make it even more powerful imo.
imo a lower octave and a basic eq either parametric like on the dod boneshaker or a shelf at 120hz and 4khz and two bell eqs at 500 and 800 would make it midblowingly powerful imo
with the eq we could have the difference from fuzz factory to fat fuzz factory inside it to push the amp sim more into muddy territory and the lower octave just sounds awesome too