For me, part of the joy of a vintage fuzz is the way it interacts with different guitar pickups and the volume pot. If you have any vintage style fuzz (such as those based on a Fuzz Face circuit) then the whole design of the thing is flawed but in a wonderful way..... It makes a circuit with your pickups. A guitar amp or more modern pedal does not do this.
For this reason, I think a profile of the amp with no fuzz and then use the fuzz in front of the Kemper. I know this isn't what everyone wants to hear but ultimately the Kemper has a high input impedance and so will not act like a fuzz pedal in terms of your guitar volume.
Just my 2 cents. Or pennies actually as I'm British
actually, to my knowledge and experience the Fuzz Face is quite unique in this respect (turn down volume just a little and the fuzz is almost competely gone). I have plenty of fuzzes that do not react like that.
The Fuzz Factory is also known to be very picky about the input, so I wouldn't generalize the here mentioned difficulties with profiling a Fuzz Factory to be the case with all fuzzes. In fact we already have great profiles from the Musket Fuzz and the Pharaoh pedal and more in the rig exchange.