I don't know if I have more experience than you, but I have worked with lots of aggressive dogs over the years. Working in LA as a pet dog trainer, I was one of the only trainers who was willing to work with aggressive dogs. Peeps in LA are not fighting for business, so I was friendly with a lot of other trainers and many of them sent me the aggressive dogs they didn't want to deal with, i.e. the ones that really bit or were scary.
My general plan of attack is to keep everything very calm and low key in the beginning sessions. I don't make eye contact with new dogs if they show any sign of nervousness around me. I focus the training on reward based exercises to teach the dog how to learn and to have a positive association with me and the training. When I add correction, I add it in a way that does not make dogs nervous- steady collar pressure with a release as soon as the dog complies into the known behavior (usually "place"). This type of correction is not quick or violent but can be very effective if used properly. I do not use any collar that might panic the dog. Usually just a normal flat collar, occasionally halti, but no chokes and no pinches in the beginning. I make sure all my movements are very calm and deliberate, especially any leash corrections. I also keep the focus on the food. If the dog isn't working well for the food, I will not add correction to the mix.
I believe compliance to leash pressure is primarily a learned behavior. Once the dog really understands how to "turn a correction off" through compliance, then I will start adding "distraction". In the beginning I use food or other mild distractions. I teach the dog that the food may drop to the floor, but the only way to get it is to stay on the place (or sit or down). I let them think through these types of problems, rather than trying to force them into compliance. I will let a dog get off the bed and stand with the collar tight and anchoring them in an uncomfortable position off the bed as long as they want to fight the leash. The collar is flat, so it's really more of a power struggle than any real "correction". When the dog gives up and goes back to his place, I give him a treat from my hand. By the end of the session I am at the point where I can pick the treat up from the ground and hand it to him- showing him that if he just listens and waits, it will come to him, from me.
As his understanding and compliance improve, I move to adding distraction in the form that he tends to be aggressive towards (in the case of Nyx, that might be his handler getting a little stimulated to excite her). I am careful to add it in a controlled way, keeping enough distance and managing movement and noise enough that he is only mildly stimulated. If he complies and stays on his place, he is rewarded with food. If he makes a mistake, he is corrected and allowed to think through the steady correction if he needs to and the distraction is stopped completely to allow him the space to calm down and think. When I am doing this, I make sure that the rewards grossly outnumber the corrections. This needs to be primarily a positive training exercise for the dog. I think many people get over-eager about the corrections once they introduce them and end up correcting way too much and stimulating the dog through that stress rather than calming them. I prefer to take my time and work a lot of this with really positive sessions, keeping the focus on success and progress.
I gradually increase the distraction as the dog's understanding and reliability increase. I will also move from the place to heeling and sit or down stays so that the person has tools to use at the house and in the neighborhood and in the park. But I tend to use a static position anytime the dog over-stimulates. Dogs trained this way will see a dog or person coming on the trail and offer the down without any prompting. They learn to "turn themselves off" and develop a lot of confidence about staying in that position and having the person keep them safe from the "threats". They also come to see that the people and dogs are generally not threatening. Of course, if you let them get attacked by a loose dog (or crazy person) you are going to get set back.
In the case of a Schutzhund dog or other sport dog, you also have to teach them how to get stimulated but focus that into the right behavior. I do the same sort of training, but will occassionally release them into the drive object (toy, sleeve, jump, sheep, etc.) as a reward for compliance. I never release them if they are "scattered" and unfocused with their drive. If they whine, bark, move their head in a crazy, unfocused way or any of those other signs that they are getting too stimulated to think, I down them or place them until they are calm, showing them that they cannot earn the reward that way. Then I start the exercise again (heeling or start line or back transport or whatever) and release them to work when they are clear and focused on the exercise at hand.
I think your big thing with Nyx would be to get a reliable down so that everytime she starts jumping at you, you can get her back under control and step away from her until she is calm. She wants to interact with you. Show her that when she acts crazy you leave her. She can only keep you if she stays clear and focused on the exercises. Is this similar to what you have been doing? Does all this sound familiar to you or is this different from your approach? I'd be interested to hear what you have been doing and how it is working and why. I like the whys
Maybe you notice from my posts that I get a little into the details :lol-sign: