It would be really great if you could make it so that playing the Kemper through a normal guitar cab or similarly colored cab could be made to compensate and sound more like the source material, so you don't have to disable the cab section.
My idea for this is if you could profile your output cab and it's poweramp, and then have the KPA apply the inverse of it's settings to the output EQ for you (or maybe as a more complex "Cab" model applied in negative against the inbuilt cabs) basically it would compensate using the "output profile".
Admittedly it would result in it incorporating the microphone in that compensation profile, but I think even with that it would be much closer to how it should sound, or at least close enough as to solve the problem.
(this comes up in relation to the thread talking about how all of the clean amp's profile is in the cab section, so obviously you don't want to disable that in a live setting).