I wonder how the footage would of looked from a handlebar mount which should be more solid.
Equipment mounts are generally a lot more shaky than body mounts, as they take vibrations from the bike. The only time I’ve had one not do that is when I CNCed a massive double clamp to mount a camera on some fork lowers (Bar mounts also tend to look terrible, as without any of the bike or rider in frame to contextualise the shot, it gives little sense of scale or speed).
Head mounts suffer on rough trails unless you have a strong neck. With a chest mount, you either tighten it down to the point where it’s a little bit uncomfortable, or construct a harness with a longer baseplate to give the camera a more stable base.