Hi Straight and level....I fly both, and trust me, all well and good as you point out in performance theory, triple is not an issue. But the 787 on a combined ATM and derated take off FCTM states that in extreme conditions you may have altitude losses but overall the gradient is positive....well in VNAV you get 100/200 fpm until flap retraction and when CON kicks in your N1 goes up 10%....and ROC up to 1000 fpm or more