Checkboard and 411A-- it is obvious from your comments that you have never seen these types of charts-- very different from the usual "single flap setting" performance charts used by most airlines. The usual rules do NOT apply. Often ONLY "improved climb" is offered for example. Each page can have multiple flap settings depending what is computed to be the optimum flap for that temp/wind/runway combination.
411A "improved climb" is what you refer to as an overspeed takeoff where excess TODA is used to accelerate the aircraft to a higher speed to improve the gradient in the initial climb. It can result in MUCH higher speeds than usual.
Mutt- I will try and get a copy to show you-- it may take a day or two! Meanwhile if anyone else out there is actually familiar with these strange things maybe they can add their thoughts!