I also went through a great deal of effort to include in our ops manual the idea of adding speed for takeoff. EG; if you are below max takeoff weight for a runway...bug up to max takeoff weight speeds and have a cushion on takeoff in semi windshear conditions
Now included in modified form in the Boeing 737 FCOM. Quote:
"Consider increasing Vr speed to the performance limiting gross weight rotation speed, not to exceed actual gross weight V2 +20 knots. Set V speeds for the actual gross weight. Rotate at the adjusted (higher) rotation speed. This increased rotation speed result in increased stall margin and meets takeoff performance requirements. If windshear is encountered at or beyond the actual gross weight Vr, do not attempt to accelerate to the increased Vr but rotate without hesitation".