My fear is that the sound of the PA will be much different to the sound that I have with the Kabinet's Kone Imprint mode on stage. When I now test the difference between Kemper Kone Imprint Mode and FRFR Mode, I hear a big change of the sound... will that be same with Kemper Kabinet Kone Imprint and PA?
Yes, it will IMO.
This is the reason I switched from using Imprints (which was great) to FRFR in live context as the change to the PA will be much smaller with latter one and the profiles will translate easier.