No way to just turn the effects off? That would be a super downer for me with respect to this amp. I'd want to use just the "power amp" section, without the preamp or the FX. If this is not possible, I can't imagine how it would be good with the Kemper, though it's all YMMV and I don't own this. Running into the FX return would be the option of choice when running the Kemper into an amplifier for me.
The aux input bypasses the internal effects, using only the power amp, which is how I was using it. I was answering a specific question ...