Yes, there IS some digital aliasing or fold over distortion in the OD/distortion stomp section.
It is of course made even more noticeable when run into a distorted profile.
That said, the actual amp profiles DO NOT have this problem.
I find I do not need the distortion stomps with the gain flexibility with in the amp profile.
So its not a problem for me. I am very sure this issue will be addressed in the future.
For what its worth Boss modelers are FAMOUS for having digital aliasing or fold over distortion even with in their amp models.
So going back to your Boss products is not much of an answer in my eyes.
Profile your Boss unit with the OD/Distortion on and you will have what you want in the Kemper with out the Boss aliasing plus much more tone flexibility.
Bill Ruppert