When back angle flying I'd use the back-sides of my hands against the wind, as it natuarlly opens your shoulders and chest, and therefore makes your body a more prominent wing, which in turn makes your flying more powerful. When you are angle flying on your belly you are using the palms of your hands, hence you should use the oposite when back flying. Just my two cents :) Side-note, this way of back flying will also allow you to use your elbows to initiate the transition to belly flying whilst maintaining control of your heading with the back of your hands

Again, great content. I'm binge watching all ur angle flying videos 👍✈️👀

Very nice instruction vid !!