Just added some profiles of a Fender Blues Jr and Vox AC15CC profiled at the same time. I used to run multi-amp rigs and wanted to experiment to that end with the Kemper. My method was a bit primitive and, while all of the results may not be stellar they are not as bad as I thought they would be. Here's how it went down: Both amps facing directly at one another with a single SM57 between them. KPA direct out > mixer, mixer main out 1> Fender, mixer main out 2> Vox, SM57 > Return Input. I threw a thick blanket over the entire setup to force the mic to take the signal with no bleed.
For my main rig I run "Monitor Out/Cab Off" into a power amp > Mesa boogie cabs. Not sure how these profiles sound with "Cab On" but through my current set up they are not bad (maybe a bit harsh to some ears). I plan on experimenting with more multi-amp profiles. I will use an additional mixer to separately mic and isolate both amps to get more refined results. I'll keep you posted. 