Gluten Casein free ‘autism’ diet

Master 6 has level 2 autism. Bright, funny, memory like a genius, not a multitude of sensory challenges- but... cannot sit still in school (new to prep this year), can’t focus or stay in the group. Some big emotional challenges.

I have cut out refined sugar in our diet and eliminated pre packaged foods- everything is made completely from scratch.

Not a big change in emotional regulation or impulse control.

I was just browsing google about gluten free and Casein free diets for Autism.
The gluten free lifestyle is not something I can push into the whole family right now- but dairy/lactose free diet- that’s manageable!

I would love to hear some feedback about the above diet- have you tried one/both? Did you see a big difference?
My son is verbal, emotive, affectionate- I would be hoping for some improvement with impulse control and attention span at school. Obviously I can’t custom his improvements, just for for a picture of his current abilities.

Any advice or suggestions are most welcome :)
Thankyou in advance.