My DS9 (almost 10) has an ADHD diganosis. We have used his diagnosis to get accomodations in his HG classroom that include additional time to complete work (this is really only used when the work is writing or below his level) and less problems to indicate mastery, allowing us to type for him on larger projects and/or him to type. He can also chew gum in class to help with focus. Your post sounds very familiar to me because still I wonder how much of his issues are giftedness (ie still not quite fitting in the classroom) or ADHD. There are many other similarities to my DS (writing, fine motor, still occassional major meltdowns, intense need for physical stimulation - very active, resists (ie fails to increase speed for) timed activities) and what you describe with your DS. I have said many times I don't think he has ADHD until he does something that shows he does. It's definitiely harder when school is in session.
My kid has never been the 2-3 years lagging in maturity and/or executive function that I often read about or that blackcat mentions with her DS. I have seen significant growth in the last 2 years. I will tell you what we did in terms of trying to find the right educational fit before we went down the road to getting the ADHD diagnosis.
He was one of the oldest for his class so, although he was a little immature, he skipped a grade mid year from 1st to 2nd. After that, we got him into a HG self contained program in a neighboring district. The classroom was a 3/4 combo so he was still 7 while a few kids were already turning 10. A few months into it, he was struggling socially and with written output (he still struggles with it - I guess when I say struggles - I mean he cannot output what is in his head)so we had him assessed further to see what else could be going on. We essentially had the same conversation with our neuropsych that you have described and just decided it would be better for him to have that protection and to not be penalized because he is slow and immature. He is much better and quicker at work that is at his level so when we have that, he seems to be able to focus much better and pick up the pace a bit.
He is PG by DYS standards and we have not medicated. I do give him omega daily and a multivitamin and we try to eat healthy in general. We are an active family so we try very hard to have some fun activety as part of our day - with school and work it is not always possible but on the weekends we always do something physical. My husband wrestles for fun regularly with my DH and that seems to work to feed his senses.
I tell you all this so you know what we have tried before and/or during going down the road of a diagnosis for him even though I cannot (nor do I think anyone really can) tease out what exactly is ADHD and what exactly is gifted intensity/overexcitability.
Good luck.
