So I brought him in and took his blanket off and then let him burn off some energy in the indoor. He was more than happy to buck and cavort about for about 10 minutes. After that he allowed me to catch him quite nicely. I put him in the cross ties and tacked him up with a balancing rein and took him out to lunge.
He was quite the monkey at first, but quickly he settled into a nice walk rhythm and on to some nice trot work. In the time that I was watching him cavort and buck about and in the time I was watching him in walk and trot on the lunge, it became apparent to me that he is very tight in his back. He needs to get stronger through his topline to help him carry himself even better. He is such an extravagant mover that he looks impressive, but when I really look at him, I see that he is really just flinging his legs rather than coming over his topline and using his core.
So on the lunge, I let the balancing rein encourage him to come down and forward with his neck, which he showed some nice effort and result at in all three gaits. Work like this will really help him develop.