Well, I know I've scewed it up many a time so far LOL.
A piece of advice that sticks in my mind was a comment by DS's first Psychiatrist. He said to change our viewpoint of what we expected from school. First, no school situation is a long term solution. If it works for 6 months great. Longer is even better, but be prepared to review and change things on a frequesnt basis. Second, was that the criteria for choosing a school option was not what is the best place for DS, but rather what is the least neagtive placement. That made me feel really sad for along time, but it did help DH and I to stop second guessing ourselves so much.
Form the sounds of your post your son is happy there even if not challenged. Do you have other options that would provide more challenge at his age? If he is content to do the afterschooling with you, he is still advancing and not forgeting how to learn. He is getting the social aspect of kindergarten as well as some academic stuff at least in the specials.
My 2 cents is to let it ride for now unless things change to the downside. However, it may make sense to look into all your options for 1st grade and see if there are better options either at that school or elsewhere for next school term. I think there was another recent post with a similar question that may have some better suggestions.
Good luck
