I like the fact that he seems patient.
While he is small, he does not look like a late developer (like Lingard or Rashford). Not much he can do about his size, but he can try to turn in into an advantage. It takes less energy to move a small body around, and he should look to develop his stamnia. Players like Iniesta, David Silva and Kante plays with aggression and intensity that bigger players will not be able to match. I also like how a player like Fraser have taken care of himself.
I do not think Gomes is a natural talent in terms of stamnia (just my impression), but it should be the easiest part of your game to develop. At Man Utd you would think he is at the right place too, considering we can offer him both time and some of the best people to tailor workouts for him. I believe that he has the talent to make it.
It is just down to him and his mentality/hunger. Is he a Scholes, Beckham, Giggs or a Wilson, Macheda, Januzaj? Most talents are in that last group. The next three years will be the making of him.