Things are changed up now!
Aslan loves the new treats. I've been cutting up apple and sweet potato and trying to alternate that with the extruded feed treats. He only gets them when I ride, which makes riding a heck of a lot more valuable. (I learned that tip from Shawna too). He gets small amounts of extruded feed for ground work and misc interactions but valuable treats go towards riding. Apparently I'm not the only one who has a horse who loved the ground work and found it highly reinforcing while the saddle work was blah.
However, I've still noticed some regression, including in our six button game in the saddle, and a lack of motivation to cooperate on various things, depending on his mood. I then realized something else: he might not be hungry enough. I don't believe in starving an animal for training, however there is fine line. I learned from training parrots that a full belly can also kill motivation. I know it's not all about the food, but certainly, if I don't have something he wants to work for, then cooperation will only result if he is interested in the task we are doing. So I I want to work on trotting and he wants to work on poles, obviously he is going to heavily resist trotting, just like what happened the other day. While I don't mind doing stuff that interests him during a lesson, sometimes we have to do other stuff too. So it will be very frustrating to me if I ask him to do something and he tells me to go to hell, because he would rather touch the cone for the next 20 minutes.
So this doesn't mean I'm withholding food, it just means I'm not just giving him a buffet all day.
He was on a round bale with a slow feeder, but he has been able to defeat it and rip through the net. He would stuff his face and when it was cold that was fine because he burned it off quickly. Now it is warm and he just stands around like a fat panda. I put him on flakes with a slow feeder. My net is a better quality and I can replace it cheaper than the round bale nets.
He also has two other problems related to free access food. First he plateaued on losing weight despite the fact I ride him 3-4 times a week. He still needs to lose more for his own health. Second, he was being aggressive to the other horse sharing his round bale, and both were coming up with little injuries. So by putting him on flakes, they were able to move him and the other horse and avoid this issue.
Riding outside has helped a bit. I focus on other things and just do small bits on the more boring stuff. I've been slowly taking him out near the field and going further to give him more courage and less fear. He spooks at stuff but is generally alright.