I have the luxury of having a good sound man who travels with us so not sure I'm the best help for you. But, what I can tell you as a former tube amp user (Mesa Roadster miced with Sennheiser E609 sent to FOH through snake) is that the Kemper signal direct out to FOH is much cleaner...well, pristine actually...compared to the miced up tube amp. So many variables are taken out....mic placement, stage noise bleeding into the mic, etc, etc. Any decent sound person should be able to keep your sound relatively close to the sound you hear when you play through a good set of headphones or monitors at home. I think you will run into issues if you are trying to get your FOH sound to sound like the reference cab monitor you have onstage. I'm sure others will chime in on that but my thought is that you want to match FOH as closely to what you hear from your Kemper when it is not influenced by guitar speakers. If what you hear through headphones and/or monitors at home sounds great to you, assuming your PA is decent, it should sound great through FOH with minimal EQ tweaking from your soundperson. I play my guitar through wireless so I do like to walk out front occasionally during a gig and I might give some very minor advice to the sound guy but he's usually spot on.....other than, my guitar is never loud enough
EDIT: I should also add that I just played my first gig with an EV powered monitor in front of me rather than a guitar cab behind me and loved it. Reason being, it's close to FRFR, in otherwords, much closer to what it sounds like FOH. In this way, I feel that what I am hearing onstage is relatively close to what is going on FOH. Hope that helps!