I have another device from Kemper Amps, an Access Virus TI Snow. It is an amazing synth. But it too has its limitations and will tell you when you are taxing the system too much. When that happens, voices get dropped and other insanity.
you cannot compare the two in this regard. a synth is something entirely different to an audio processor like Profiler.
As far as processing power, there are certain effects that add latency to the Kemper, for example, the transpose or pitch FX. I'm assuming this is on account of processing power, though perhaps it is on account of just the time required to affect the signal.
That said, I have external gear that does not exhibit the same issues at least as far as pitch FX are concerned.
pitch recognition in the digital domain requires time. that's true for your external gear as well. some prefer this resulting latency to be static, others choose a dynamic approach. it has nothing to do with calculating power.