Video of my son, what do you think

My son is 11 5 ft 6. He has great location and pitches 50-53 mph.
What advice can anyone give?

Thanks for the help.

Looks like a good post but might want to try and limit the crossback a little, solid arm slot, I like how he gets a nice flat back. I could see a little more length to his stride this might also increse the action of the right leg coming off the rubber, this can help decelerate the arm. Glove side is dragging just a little, like to see him pull the glove back to his body more.

He really seems just to guide the ball in, I would like to see him really throw the ball. What about stretch?

Great to get feedback. We live 3-4 hours from any coaching. The advice helps. I think he gets a slow push off the mound. Throwing from the stretch may help. Any other thoughts is a great help.
I really appreciate your input. Thank you.