We aim to fly the second segment at V2+20. At 1500 aal we wind the speed up to VFTO and the flight director commands between level flight and a very shallow climb while we accelerate. Personally, i am not a fan of using alt because a genuine engine failure is an adrenaline inducing event and its neater to keep the engine failure scenario as close to the all engine scenario as possible. I cant imagine it makes a lot of difference from an achieved profile point of view. If you balloon a tiny bit using alt hold so what - youre still at max chat on the remaining engine so from the point of view of the total energy in the system it must be about the same. The fewer buttons you push and the simpler it is the better in my view