11Y.O. Lefty Vid Analysis - Increase mph on via Mechanics - Help

Good evening,

I would sincerely appreciate some advice/suggestions/tips to help my son with his mechanics. He is pretty good and staying within the strike zone but we would like get a little more velocity from his 2-seam fastball. He currently throws a 2-Seam FB and a Circle Change. From my basic knowledge, I feel he does not real power through his hip rotation once his front foot lands but that is why I am asking for any tips or drills I could have him do.

God Bless

The first video was recorded at an angle from which it is difficult to analyze. It would be better if it was from straight behind home plate or straight-up center field.

The second video is from a good angle (1B) but is a little too far away.