I'm not as convinced that ducting alone will solve the melted boots/discolored calipers issue. If I slow from 135MPH down to 50MPH all four rotors will increase in temperature about 330 degrees F. That's making the gross assumption that the front and rear do the same amount of work, which they don't - it's much worse for the front. Do that 4 times in a row, and you're at 1320 degrees!
With those RB rotors which weigh less, the temperature rise is even higher. No doubt ducting will help - and I think misting the air with high pressure water will help that as well. I'm still wondering if hitting the rotors and/or calipers directly with mist is a good idea or not.
Most track organizations will not allow any sort of fluid to spill on the track - so the water will have to be consumed in the process, or the mist fine enough that it evaporates.
Sorry for the old video, but this is the type of misting I have in mind: