I am sorry about the lack of clarity. I am still learning the terms associated with the gifted world. When I mentioned acceleration I meant an increase in the depth of the material rather than specifically a grade skip.
I think the material changes each year. At least it did the two years we've been there.
They do have the older kids come down once a year for a presentation and he really enjoyed that in preschool.
Otherwise the kids are separate all day. They don't mix at all. It is a Montessori school and I wish it were K-6 but it isn't.
Last year we went to the library to supplement what was taught at school and we enjoyed it. I think the depth was just a bit boring for him last year. Going back to the space example, the goal in the preschool class was for the kids to learn the planets. They had dozens of activities throughout the month enforcing that concept. He already knew them so it wasn't that fun. We went to the library and he learned a lot more about space from us reading to him but at school it was more of the same. The 1-6 class mapped constellations as a part of their space month and the projects hung on a wall outside their classroom. Their teacher saw him looking at them and explained what they were. He understood what she told him and thought it was cool. Of course he couldn't write an essay about it or read a book about it but he understood it and would have enjoyed that activity. Perhaps they'll let him come to lectures and do that type of work. The K class has around 24 kids. The 1-6 is significantly smaller. Maybe they wouldn't mind. Anyone ever do anything like that?