Although first grade isn't really challenging him much academically, he seems to me to be much happier and more interested in school.
I think it's easier to 'hothouse' mature behavior at home and let school be a 'reasonable fit' than it is to deal with the fall out of school making a kid misearble, and eroding the child work ethic, and then trying to afterschool to make up the academics. If you can homeschool him or send him to a different school that can meet his academic needs while keeping him with his agemates, do that, but if you can't, you can't. I think having less attention by being in all one grade is ideal, but of course, once he gets into all day 2nd grade, he may need to go to Math in 3rd grade after a few months. You have to do the best you can with the kid you have.
So basically your son might cry sometimes at school. Even in 2nd grade this probably won't be that big a deal. It isn't due to immaturity, it's due to him being 'aware beyond his years' of things. You can work with him to teach breathing techniques, or just brainstorm his ideas how to 'not cry' during school while validating the 'strong feelings.' You can talk about times when you felt a very strong urge to cry but didn't because in some way you put the needs of the situation first. You can point out to him how much money is in 'tear-jearker' movies because everyone wants to cry a lot more than they do.
Eventually everyone needs to learn when to spontaniously show the depth of their feelings and when to distract themselves and 'stow it for later' - learning to do this flexibly is part of everyone's journey of growing up. And it doesn't happen over night, but I bet if you notice him being strong in any little way, and praise him about it, he'll naturally start being more flexible about what he 'shows' in school.
Example: He is sitting in the car at a stoplight and swinging his legs.
You say: I now that you are having strong feelings about really wanting to get to our destination as fast as possible, and I bet you wish this car had wings. But look at you! You aren't complaining! You aren't yelling about it! You aren't punching your sister or breaking any other rule. You are holding those strong feeling inside and being really strong about it - that shows your maturity.
I'm proud of you.
((More in 'Transforming the Difficult Child Workbook' by Lisa Block and Howard Glasser, if this approach seems appealing.))
Love and More Love,
Grinity
