But the video clearly shows a bloke jumping up and down on the pegs and the bike changing direction very slightly. If putting your full weight on the peg has very little effect on steering then how much do you think just pushing down while seated will have?

The bloke who did that video traines racers for a living and is an expert.

Like i said go out put your hands on the tank and push down on the pegs and see for yourself how it does nothing