I am well aware that you know more than me TP, so dont take this the wrong way. I dont believe your climb gradients are correct.

The 2.4, 2.7, 3.0 are for single engine climb with gear retracted 25.121

And when the aircraft reaches 400' agl, the climb gradient may not be less than 1.2, 1.5, 1.7 percent 25.111

I may be wrong though, please correct me if I am. This is a question I have also been trying to get answered... I am so confused