The hot feed may or may not be the issue or be a "hot" horse by nature but there are horses that can not sit idle regardless. They start to fiddle or destroy their surroundings. They need to be stimulated mentally and blow off some energy= have a regular job.
I even had one of those types turned out on acres and acres he would get bored and destroy the fence and act up if not rode, and I mean rode with a purpose, not just loping circles, on a regular basis.
I have found these horses to be smart and need a job, purpose and a way to engage their brain along with regular exercise.
Also I would rethink the saddle fit, maybe its the angle of the picture you posted but the forks look like they sit down on top of the withers.
Out of curiosity, how does he destroy a panel stall?
I DON'T LEAD 'EM AND FEED 'EM, I RIDE 'EM AND SLIDE 'EM.