So besides the wattage handling on the KPA speaker, what else specifically might be different between it and the FX-200 then?
FRFR speakers tend to have a fairly wide dispersion due to their design, Mr. Kemper brought up the "beaminess" of the Kemper speaker a couple of times, so I'm guessing that the Kemper speaker, though essentially full range, was tweaked to behave more like a guitar speaker and less like a typical FRFR speaker.
Either way, this is all just another "Hey, let's all run this for 200 pages speculating and arguing about something that doesn't even exist in the wild yet" thread, so we're all just throwing out ideas to keep ourselves entertained until the cabs hit the market.