Personally, I would think trying the bitless might help. I found that when I tried it, you had much more control than you think. I am totally against roundpenning in this case, unless you keep a line on him, since you have said the bit makes him want to go faster and stress.....I had one like that just go faster and faster in the roundpen. The most helpless feeling in the whole world-and he jumped out! Legs got tangled in the gate-it was ugly. Thankfully he was ok, and as soon as he was free he just dropped his head and grazed......but scary!