To be clear, I had no sense that you had plans to medicate...I was more concerned that, in my experience with school systems, the knee jerk response of the school to this diagnosis is to hint either subtly or openly at medication, which sometimes is accompanied by resistance to seek any other solutions...but it appears that you are already rather near that point regardless.

I hope you are able to connect with an appropriate advocate, and to get a referral for an evaluation expeditiously.

And thinking back over your earlier post, it occurs to me that some of the school personnel might benefit from some additional inservicing on ASD, if they are that quick to label rigidity (a known characteristic of ASD) as defiance. And they have a history of responding weakly to behavior.

I would discuss with your advocate the value of adding a functional behavioral assessment (FBA) to a request for independent educational evaluation (preferably conducted by a BCBA or psych), given the testing behaviors, and the evaluator's interpretation of classroom-observed behaviors (writing problems, and being dropped down a level in math for his behaviors) in that light.

I think this is a pretty open and shut IEE request, actually. The referral question included writing difficulties. They didn't successfully assess his writing skills. He has a history of behavioral problems, and the evaluator ascribed additional academic problems to his behavior, but they didn't formally assess his classroom behavior. Based on the information you've provided, it seems clear that it is a defective evaluation, and the district should pay for (or contribute to, depending on your state) the independent eval as an appropriate remedy.
...pronounced like the long vowel and first letter of the alphabet...