Platypus, thank you for mentioning that it better to reframe boredom in a more positive light. That's seems obvious now, but hadn't occurred to me. The teacher is very sweet and from what I can tell very good with the class, so I don't want her to fell that I think she specifically is doing something wrong.
The preschool is a full day and they don't have a half day option. Although, nap time is the last activity of the day, so I'm starting to consider picking him up early and having him do his quiet time at home. I'm currently staying at home with the new baby so this would be an option, at least for the time being.
I did talk with the teaching assistant today and she confirmed that his behavior has improved, but the disruptions are still a problem, particularly at nap time. They've ended up typically moving him to a different room. To be honest, part of the matter is he is a difficult kid. It takes a lot of energy to parent him and we have to set very firm boundaries. He's clever and figured out that the boundaries and school aren't as firm and he gets lots of second chances, so he feels he doesn't have to behave as well at school. We've found for ourselves that he's the kind of kid that if you give him an inch of rope he'll hang himself.
I do want to try and stick with the school. DS really likes it and is making friends. So maybe your advice can help me tailor his experience a bit.
