Figaretto,
I believe your idea of using the normal Vr and climbing out at the improved V2 doesn't hold up:
1. Imagine an engine failure at Vr - no room to accelerate here to achieve your 1 ENG INOP best angle speed (v2). You've just defeated the purpose of your augmented speeds.
2. I believe FAR 25 specifies V2 as equal or less than 1.2 Vr. Correct me please if I'm wrong. Don't have my perf books in front of me now.
Cheers,
AO