I am definitely not a pro...haven't even been to a track yet (but I did stay in a Holiday Inn Express last night....actually I spent the night in a frickin wooden shack in Afghanistan that was 36 degrees inside...5 outside, d@mn it's cold here.)
Alright back on track. I have experimented with different things. I have used the two finger method on the clutch and brake but after a while of riding my clutch fingers get tired so I switch back to four. It is more comfortable to use all four on the brake although I try at times to use the two on the brake or cover the front brake in moderate to heavy traffic. It just depends what traffic is like and if my hands are tired from riding. But I do agree that covering the front brake with two fingers cuts the reaction time by ~.0249secs and at times is the difference of avoiding a hazard or colliding with one.

"Frag the Weak, Hurdle the Dead..."