shellymos, interesting that you post this. I don't have any advice, but I have had a very similar concern.
This year, DS7 has had more instances of "can't sit still". Though it's not quite what your DS does, there is the tapping and bouncing and rocking in his chair. At home, he will just stand up, sit down, rock back, stand up, sit down, tap, rock back... it's almost like he has to go to the bathroom and won't go. Of course, he doesn't. He's restless even when he's focused on things that used to have him still as a statue.
I have been concerned with ADHD, but he's not really that hyper otherwise. I have ADD, or at least I am on ADD meds which help eliminate many of my executive function issues.
This is actually one of the reasons that we decided to get him on the lottery list for the Charter School in are area (so glad he got in!!!). They have three non-curriculum focuses that differ from the regular public schools here. 1. the lighting. There is more natural and soft lighting. 2. muted paints on the walls. bright colors can sometimes overstimulate and/or distract kids. 3. MOVEMENT!!!! They require their teachers to have their kids up and moving (even if it's just shaking the "sillies" out) every 20-35 minutes!!! This one alone will help DS (and DD) tremendously!!!
Anyway, I didn't mean to make this about us, but I am interested to read how everyone responds!
