Thanks guys! Yes, I had to change up my approach in order to learn the motion correctly.
At first I kept hitting a brick wall where it would feel really tense and I couldn’t go any faster. For me that was 125-130 bpm 16ths while playing these 1nps lines.
What I ended up doing was setting the metronome a little bit faster than my max and then just kinda tryin a bunch of random movements in my picking hand and just flailing my hand around trying to make it work. It was really awkward for a bit but eventually I stumbled into this feeling where I noticed it felt lighter and smoother. It’s tough to articulate what it was but It felt like my forearm was twisting more than it does in my normal motion. After that it would be hit and miss for a few days. Sometimes I could get that smooth feeling and other times not until it got in my muscle memory.
My main advice would be to try to play the Crosspicking lines fast and pay a lot of attention to how it feels in your hand. If you notice it feeling tense or like you can’t go any faster then try just randomly moving all the joints in your wrist, fingers, and forearm while you pick and your brain will figure it out eventually.