Well, I tried the rope halter. He was actually quite happy in it as far as his mouth/head, and steering is okay. I had him carry his Mullen mouth with no reins attached while I rode off the rope halter underneath and I didn’t hear or feel him chomp at all! Definitely less power steering in this setup than in a bit, but more than the side pull. I may try a different size rope halter tomorrow and see if I can make it better.
I still get the feeling that if he locks his neck and wants to go left, I would not be able to pull his head around to the right, for example.
It was good information, though, telling me that whatever he’s got going on with the head twist appears to be bit and contact related rather than general riding.
Here’s how I have it adjusted. Maybe TOO high?