With KC, your best option is to put Force of Nature on the same keybind.
And to manually move to each window quickly, clicking while you're in each window.

I've heard of people who use KC, and have an HKN script purely for mouse broadcasting.

Aside from HKN, IS Boxer is the only program I know of, which has quick and accurate mouse broadcasting.
Basically, you can build it right into your dps key, so it turns on until a click has been made.