From what I’ve learned this is more nervous system excitability, than technique.
Whats intresting is he has both hands twitching fast, I personally have greater speed with my right than left. Though after some stimulants, my hands can do very similar fast repetitive motions like this. I made a thread about Jason Becker few years ago wondering if his nervous system was highly excitable and perhaps what caused neurotransmitter toxicity from consistent repetitive and fast use.
When neurons get stimutated to much they die as far as I’m aware.
Though I’m not saying this will happen to this guy, more it’s an intresting avenue to look into.
We all experience this as we get older, our nervous system slows down and we can’t react, feel, move etc as fast.
This guys speed is impressive, I used to do same thing button mashing in various video games, I can only do it right hand tho, makes me think I should switch to playing guitar to lefty.