Too many times you see crews failing to nail a simple request like "approximately 40%", will not wait for the engines to react and push even more forward asking 60-70%.
Couldn't agree more. Seen that in 80% of simulator sessions in the 737. Just as illogiocal are those who overshoot the approximately 40% N1 advice during the rolling start, then hurriedly reduce power back to approx 40% N1 when they realise what has happend and then shove open to takeoff power hitting TOGA on the way, oblivious to the fact that they are eating up runway distance and invalidating V1 in some cases.