Might be a stupid question, but here it goes:
As I understand, Improved climb is obtained by using a higher Vr, to obtain a climbout speed which is closer to the max gradient speed, thus giving a steeper climb gradient, but a flightpath which starts further down the runway, and thereby closer to the obstacles in the flightpath.
Would it be possible to use the normal Vr, but accelerate faster to a speed above V2 after liftoff, to obtain this steeper gradient? This way you wouldn't use any extra runway, but you'd still have the advantages that improved climb would give you.
...or?
Nick.