Question about preschool table activities

Hi everyone! My kiddo is about to turn 4 in a few days. He started preschool in October and he has an IEP for speech development, social skills and self-help skills. He used to be very very terrified when we dropped him in the initial days because it was for the first time that he was leaving home ever. Within a few days, he adjusted to be in the classroom without crying as much but drop offs were generally tough. The teachers know about it. He attends school directly after ABA. So, he goes to ABA 8:30 -11:30 and then starts with the PM session that is from 12-2:30pm. He has learnt to be a part of the classroom and engages in free play and can sit and listen in circle time with teacher sometimes prompting him to sit still and not talk over others. So, in that two and a half hour schedule the kids have ten minutes for art and craft sitting on the table in a group. In these three months, I have not seen him being there at that table and i have not received any craft work that he did there. I see it in the pictures that the teachers share where other kids are doing that. When i asked the sped teacher she said we are giving him time to adjust to the routine. In my honest opinion, i am assuming that only because he is passing his time quietly without creating any ruckus the teachers are okay with him not doing that ten minute activity. They say that we can’t force him to do it, however he still needs a little push and i say that because i have seen that at home and even the BCBA sends home the art work that he does. She also tells me that you need to push him a bit and in a few days he can do it. My question is , how do i put it across to the teachers in a good way that they dont get offended and try to push him a little so that he learns that he can simply not deny an activity that everyone else is doing in the classroom. As per the BCBA, this is setting a wrong precedent for him by setting an example that boundaries are flexible and he can refuse. If this thing continues then it looks difficult to think about kindergarten. I agree there are other things that he needs to learn as a part of his IEP but then that doesn’t mean that he can escape the “only” academic activity that they do. I need your help to clarify this with the public school so please share your suggestions. Thank you! Do you think i need to look for an alternate school if they are not able to support with the academic stuff? They say that he is learning to follow instructions and imitating his peers. I am confused!