This looks awesome. It looks like @Bill_hall’s wrist technique, i.e. pronated, with the thumb-side anchor. And as others have pointed out, there is no forearm or elbow here, this looks like all wrist. This style of playing allows both upstroke and downstroke string changes, so you can do scales and arpeggios and so on.
As far as the motion, there is no stringhopping and you have no speed limits. Also the pick attack sounds nice too. Great work on this.
The only “wrong” thing I’m hearing is that when you speed up, you start picking multiple times per note, randomly. That’s not a picking motion or string switching issue, that’s hand synchronization.
Can you do chunked single-string patterns like chromatic fours, the Yngwie six-note pattern, and so on? I would try those. I find the fours to be the simplest, just 1234 or 4321. You don’t even have to move, you can just do that in one position. If you can get that, then try shifting that around flight of the bumblebee style. If you can get that, then try two-string patterns like 1234 1234 on one string, then 1234 1234 on another string, then back to the original string, and so on.