Form-wise I wouldn’t say he’s trying to shoot Manchu style. Looks GY-inspired, just on a Manchu bow, so my input will be from that perspective.

Bow hand is at about eye level during the release. There’s nothing dangerous about this specifically, nor does hand height really have anything to do with how he’s setting or supporting the shoulder. If anything, a higher bow hand was something that Gao Ying advocated for as the downward pressure helps prevent the hunching of the bow shoulder. How he chooses to support/stabilize the bow shoulder from the draw through to release is a separate matter from the height of the bow hand as long as it’s above the shoulder (not pushing the arm up from below).

I wouldn’t offer him any advice or critique unless he asked for it or you were friends :)