This is an aside to the IEP. DS made transition from a school with similar philosophy to montessori to the public school. There was an adjustment period. DS's teachers was lovely and I met with her 2nd week of school to talk about DS and the transition. DS struggled with all the extra rules. Eg. lunch had more rules about where to sit, how long, once went on the playground you can't go back to eat as there's another class coming in. Some of these rules weren't communicated to DS or he didn't hear them eg. he told me didn't have enough time to eat and had to leave tables at certain time, turns out you can stay longer but must move to one of the front tables, so next class has room.
I told DS that the public school has more kids and rules have to be different, couldn't be as flexible as his old school. I checked in with his teacher to get clarification as needed. He adjusted, but first couple of months we heard complaints about the rules.
Just thought I'd mention this as a FYI.