I have seem the same results. Wind might wiggle the rear end a bit but the head goes where it wants to.
Im still using 3x 4inch feathers so i get a little more wind kick but the head pulls it right in every single time. I was hoping to experiment with smaller fletching but the summer has got away from me so i will be hunting with the 4inch feathers this season. But this video just makes me want to try smaller even more.
Thanks for sharing.