In my experience, no. There are studies that have shown Fish Oil and Magnesium to slightly improve some memory functions over time, but caffeine or actual prescribed meds from a doctor have been quicker and had better results.
At least for the ADHD, I haven’t found anything for the autism front.
Physics says both use the same amount, just one is spread out more and the other is all at once. I don’t have the formula, but basically it takes the same overall effort to stop an object regardless of if it’s slowly or very fast.