I'm no expert but I have a little experience as I took care of my ex's nervous (as in would thrash around and poo everywhere if you tried to pick him up, and constantly be trying to run away - FAST) jungle python for over a year. After a year he's like a different snake. Very calm. He's head shy but that's pretty normal in snakes; he's relaxed, slow moving etc.
I know what you mean by the fast/stressed movements (I know nothing about neuro though so I'm writing this assuming it's not neuro). Since he's two and generally past the bitey hatchie age, you have a better chance if he's just not used to being handled rather than he's just a flighty snake - but I believe almost all animals can become tolerant of you (if not "tame") so even if he's just flighty, depending on the time you put in he has every chance of becoming more confident around people. Basically with me, it was time and patience
This snake was a yearling at the time.
First I got him used to being handled for short periods at a time, and gave him ample warning - I used to take out his hide with him in it, and transferred him to a branch from his enclosure because there was a better chance of him staying on the branch than on me. I always moved very slowly, making sure to support his whole body. Never got near his face/head or tail. I'd handle him for a few minutes every couple of days, then built it up to every day. Once every so often when he was being calm, I'd give him a very light stroke on his back; at first that was enough to make him run for his life but it's surprising how quickly they get used to it once they know they're not going to be eaten! From there I went to quick pats on his neck, stomach etc and if I'd continued working with him I'm 100% sure he wouldn't be head shy today.
So anyway in about a year, he went from desperately trying to avoid human arms to happily coming out and chilling on you. I remember when we upped his food size to medium rats, he suddenly became very confident and started hanging out in his enclosure instead of always hiding, and suddenly I could trust him to not make a run for it if I put him down on the couch/bed. I don't know what that was about but it was a massive, instant change.
Good luck with him! I know it's frustrating to interact with an animal that just wants to get the hell away from you, but when you see the results it's really rewarding