Zappy collar controversy

I have nearly 1 yr old ACD/Aussie mix that is the BESTEST boy…. Except lately he hasn’t been. He’s been deliberately ignoring commands, and took off after a deer on a hike the other day. I have been considering using an electric collar. I’ve had great success with them before, but Stormy is different. He is EXTREMELY sensitive. He can be reactive if he feels threatened, and if he does something naughty and I tell him “no” he acts like he’s been beaten within an inch of his life. What are y’all’s thoughts on the electric collars with sensitive ACDs? Any other ideas?

P.s. I don’t have money to take him to a specialized trainer, and he’s a smart boy. He’s passed obedience training with flying colors. I’m going to do something about it myself. He’s at the age where you can almost see the wheels turning while he decides whether the milk bone in my pocket is worth doing/not doing whatever mom says. Lol, see “ate whole bird” incident for prime example.