After much deliberation, and evening-time self massage of sore muscles, I decided to try a martingale on Monkey.
Don't get me wrong, I'm not against martingales, I've just never used one before now, and I was hesitant to drop my learning the proper application of a new piece of tack on top of everything else I was asking of Monkey.
I should have done this months ago. No, really.
I never realized that the martingale provides leverage such that he can't pull my arms as hard as he has been. I never realized that it would apply pressure in such a way that he didn't want to pull as hard.
The martingale is my new friend.
Now, Monkey has been doing really well, most of the time, but his temper tantrums have become more insistent. They're shorter, and fewer between, but when he gets it in his head to fit, they're more intense. Fortunately my old proficiency, earned on the back of a cutting horse that liked to surprise me, is coming back, and he hasn't managed to unseat me again.
So, the martingale made me happy, because when I put it on him, it was like I was riding an entirely different horse.
It has moved to the top of my Christmas list.
Meanwhile, I've started taking my feet out of the stirrups to... ahem... encourage... Monkey to move, since he's begun to ignore my leg cues when I'm trying to get him to sidepass, or pivot, or such. The stirrups restrict my movement, so he's getting dead in the areas I can reach in them. Plus, when he's being really lazy, I just can't haul off and poke him a good one with my foot in the stirrup, my legs don't bend that way anymore. I'm not sure they ever did.
Even more progress is being made, and the teachers assistant told me flat out that he's made at least a hundred percent improvement since the first week.