Wow what a wonderful horse, he just gives everything to you!
You are a very sensitive rider. I think one could easily ask to much of a horse like this, but you are very soft and sensitive.
Very good transitions as well!
And you both look so calm and happy together. Very nice, excellent!
Some tips (As you did ask for):
You're to far back in the saddle, so your weight pushes down on the place of the lower back of the horse. That makes it more difficult for him to round his back and find horisontal balance. Also, it is bad for your lower back and it makes it more difficult for you to follow the movement.
To fix that, lengthen your stirrups a hole or two, stand in them, rotate your pelvis by squeezing your buttocks and tucking in your tummy while breathing low, and sit back down as much as you can to the front of your saddle.
keep checking your seat, for in the beginning your buttocks will glide back again to the back
While yielding, keep your body straight and soft, remember to keep breathing or else you get rigid and it then your horse has troubles to produce the suppleness he needs for yielding, as he has an rigid 'object' to carry.
Don't hang to the inside, just keep straight, but look to the inside the same way your horse does. Put your leg back (as you did) and only give a soft leg aid when the belly moves away from your leg, then release and repeat.
This will make sure you give the aid at the right time. Keep everything light, soft and simple.
Very nice and soft canter
With the last canter, though, he really wanted to go back to trot, that was a little to much for him. That is why he went somewhat heavy and stiff on the forehand, and then the whole goal of the benefit of canter is actually gone.
That is the very reason why in AND philosophy, when the horse wants to transition down, we always let hem, for we know he must have good reason to do so