I agree with the chain over the nose. And timing. You need to pop him - hard- when he tries to turn away, and then release. Can’t out pull him. Pop and pop again to keep him off balance. A steady pull will only allow him to brace and out pull you. Sending good wishes. I’ve had a couple that came like that, and it didn’t take too long for them to decide they didn’t like the consequences.
IME, with really smart (often bored) horses, if you can stop them from winning a few times they will stop trying (until they think of something else!). My Dad’s 25yo Percheron/TB was like this as a youngster (20+ years ago!). She figured out pretty quickly that she was big (17+hh and probably at least 1500lbs) and she could do a lot of things if she threw her weight around. No explosions on the lunge, just a decision that she was done and lightning fast spin and run literally dragging people across the arena. Eventually, we just added enough people who were sufficiently grounded, and quick enough to “catch her” before she got momentum, to the end of the lunge line (and maybe a chain over the nose? can’t remember for sure - certainly nothing more than a chain over the nose) that she didn’t win. A couple of failed attempts and she moved on to something else. Thankfully, she outgrew that testing phase and generally has been a wonderful partner for my Dad for over 20 years.
I had an escapee rehabbing from an injury one winter; it was partly a young horse attitude issue too.
Lunging in the bridle with the lung line threaded through the inside bit ring, over the poll, and connected to the off-side bit ring works very well.
And a lunging cavesson with the line attached to the center ring is surprisingly effective. The trainer I worked with on dressage lunging/in-hand work said to get a cavesson with a metal piece/bar across the nose (wrapped in leather or nylon) as the weight of the metal will “connect the aids through the lung line to the skeleton,” as she described it - much better than pulling on the bit.
You can try some clicker training too, he gets a click and treats for standing quietly at the end of the lunge line, etc.
Also, I’d consider switching from the draw reins to a running martingale under saddle. Will probably prevent the ears in your nose issue but will be much quicker to release out and down when he goes forward.
Ohhhhh I had this horse. Bolting, rearing, escaping, you name it, he could not possibly have behaved more poorly on the longe line when he was started. Good ground manners in hand until we asked him to go forward on the longe line, then BAM. He would reach the open side of the longeing circle and be GONE.
What worked for us:
- chain over the nose, as described above
- having someone stand in the open end with a longe whip and creating another “barrier”, popping him in the shoulder when he threw it out and started to bolt
- if he escaped, chasing him down a la a tough to catch horse in the pasture: he does not get to just escape and then wander around. let the longe line out and start moving as soon as it becomes clear he’s not stopping; follow him into the corner; use the longe whip to send him forward, forward, forward.
- finally, on a particularly bad day, when he stopped, tried to bolt to the outside, and reared high, my trainer sprinted at him, full force, flipped the longe whip around in her hand and caught him between the eyes with the handle. it was an amazing feat of timing and precision. he came down, stared at her in shock, and I swear, did not put a foot wrong on the longe line again.
He is now a perfect gentleman to longe. For him, longeing was a necessary part of his early education in learning to wear tack and move forward on command.
Haha 
I’m not sure I can recreate that!
Another successful day lunging in the gag though. He didn’t even try it at all, didn’t even look like he was thinking about it. And he was just ever so slightly lazy at the beginning which is often what happens next after you get his number on bad behavior.
Go into the corner of the indoor arena. Use poles/standards at highest settings to create roundpen. Walk/trot/canter/trot/walk/trot/walk/canter/etc until he can move up/down transitions within a few steps obediently. Only do this once or twice a week for about 10-15 mins to avoid stressing young joints.
Once he has that, move standard/pole barrier farther out (not by much if he’s quite bad) and repeat. Every few weeks (or 3-4 weeks if he’s not getting it yet) move the barrier back. If he starts to fight/bolt in the wider space, constrain the size back down to smaller circle before going bigger again.
What worked in the short term for one horse I worked with was:
Bridle,
Surcingle,
Leather side reins with NO elastic but had doughnut set about point of shoulder high which a low setting,
Ran the longe line from inside ring on surcingle to inside bit, over head to off side of bit.
Longe in an enclosed arena, preferably a smallish one with fences high enough that he does not think about jumping. OR use an indoor.
That worked a few times until he broke the surcingle ring! :eek:
THEN came out Mr. Chain. I gave up being nice at that point becasue it was dangerous him galloping around a lesson barn trailing all that equipment. My hands were in shreds and I did not need a dislocated shoulder or screwed up ankle trying to stop and 1200 lb horse going somewhere fast. He did ALMOST jump a low arena fence but a well timed yell stopped him, surprisingly!
I had the same set up as above EXCEPT I ran the chain from the inside ring THROUGH his mouth to the opposite side. I told you I gave up being nice.
He hit that HARD, on a small circle and I pulled HARD as well and turned him HARD by walking toward his hips as I pulled. OOOoo BOY did that make an impression. It took a couple of repetitions that day to convince him it was not going to result in anything but pain. We had a very nice session after that and he lunged politely if less than happily.
The next time I started out with it in his mouth again and he held it like a bit, thought about bolting and sort of hit it and changed his mind. When he did better it went back to the usual set up of inside ring over his head to outside. Some months later, I switched to leather side reins with elastic as they have a much more forgiving design.
What really changed his mind was learning that lunging politely like a proper horse resulted in lots of good boys, breaks and lots of treats. I did lots of longing over the next months, a couple of times a week but short sessions followed by riding. The main issue was one of trust and submission. He really had neither in me and had to learn I was going to be fair and kind to him if he did as I asked but he had to do it. It has been a year just about since he last tried to break away. He learned he can kick up his heels and have a good spin on the line without having to run away to do it. Now he will longe in just the bridle with the line over his head and does very well, even in winter with time off. I have used him to longe his owner W/T/C as well and he is very good about it!
