Hauling is not only a great technique but a very logical one: if we have two hands, why not use both when casting?
High speed cameras are great as well. Now we have them available even in our phone, and they provide better image quality than what an expensive camera did not that long ago. Plenty of opportunities to learn about the nuances of fly casting just by tapping on the screen. Do you want some ideas?
Start casting in a very relaxed way, sending your fluff eight meters away. No force, almost by letting gravity to do the forward cast, trying to get the narrowest loop possible.
After a while strip one meter of line from the reel and go on casting leisurely. No force, tight loops.
Continue with that same routine till you get to a point in which you start to feel out of your comfort zone; false casting isn’t effortless anymore, loops don’t look tight now. That may happen at 16, 18, 20 m… depending on your ability, but it will eventually happen. Keep at it anyway, false casting while trying to get as narrow a loop as possible.
Then —using the same length of line— start double hauling. Do you feel any difference, both in comfort and in loop width? Can you cast tight loops in a relaxed way again?
Now something to think about while watching your video:
We have to match casting stroke angle to rod bend
Hauling bends the rod
More bend due to hauling asks for a wider casting stroke angle
I see hauling to be akin to Schrödinger’s cat: it does bend the rod and it doesn’t at the same time.
Film your casting and see by yourself.