I don't know about Kemper, but I'd bet he used it and, as always, not a single soul care (apart from PensaGhost!).
Every guitarist that contacted me after knowing MK uses the kemper asked me the same question
which is 'Is he an idiot ?'
Even Marcus Cliffe, the guy who showed the Kemper to Mark for the first time, publicly revealed he advised MK not to use it
If you don't care about a Kemper or not it's because you are an amateur who can't hear the difference of quality,
which is HUGE, especially on distorted sounds.
and btw there's nothing wrong about being an amateur, 95% of the people don't know if MK is using a Gibson or a Fender or any guitar during a concert, let alone a kemper or not, and most of them don't even know the name of the songs