This is the wrong way to look at the issue. It's not about getting accommodations to improve grades, and it's not not a competition in which "fairness" should be considered. Your son may not need accommodations. If he is learning and has the means to show what he knows, then they may not be necessary at this time. But you know he has a disability and it may impact him for some classes, some assignments, some tests so what he does reflects his abilities. Generally, when you have a 504 with accommodations, data is collected on how much the accommodations are used and how effective they are. My dysgraphic at 11 was beginning to see where he needed accommodations and where he didn't. For example, he absolutely needed to type his assignments and when he didn't do that, he couldn't express himself. Extended time didn't do squat. But in high school, he was more neurologically mature and could express himself in writing for short sentences. Then he needed extra time and forgiveness on writing conventions.
I'd involve your child in the discussions. Does he feel his work captures his efforts? If yes, then no accommodations at this point. The work may be at a level that doesn't require it. But teach him to notice when his disability is impacting him and to speak up so you can ask for what he needs.
