I don't know if anybody tried already or using it.
but routing the signal from a synth to Kemper and trying some guitar or bass sims and fx makes for some really nice gritty or otherwise unique sounds.
I tried with some of my analog synths (Moog Sub37, pulse, peak..) and its been an instant joy, works really well on mono synths.
The Trick is to use the Direct Mix on the Amp module (or bypass amp module) or just run a parallel signal into kemper.
Add to that some creative Fx and you are in Sound Design Paradise.