Not sure what you mean by uncomfortable but generally, all these motions feel smooth when done correctly. Searching for a motion that is smooth, easy, and fast is the first step. There’s no other first step, and there’s no way to skip it! i.e. There’s no way to take the unsmooth motion and “work it up” over time to being a smooth one. You can take a sloppy one and work it up to clean, but you can’t take a stiff / slow one and work it up to smooth and fast.
I can see from your clip that you’re not really moving your wrist, you’re making a tiny “motorcycle grip” type motion, which is a combination of wrist and forearm. A pure wrist motion with the grip you have looks wide and flat, not small and twisty. Did you try the rest stroke technique in the upstroke escape chapter? Try doing that with a bigger motion that’s more side to side, and see what that looks / feels like.
Also, the “Starting With Speed” chapter is new as of today and may have some other tips you can try:
In a day or two we should have the downstroke escape chapter up there as well. These wrist motions are all very similar, but you never know, there may be some tiny difference between the two motions that makes it work for you. And when you get one, you’ll start getting the others. They fall like dominoes.