Thank you for the suggestions and support I will mention those ideas to him krc...
My son also had a dramatic growth spurt starting after his 5 season and ending about 6 months ago, it was a bit of a shock as he was only 9 (he is 10 now, but will compete as 11.) Anyway, was not expecting a big spurt at that age, and I do think it caused some issues especially on rings but all over as well. He had a really nice back lever as a 5 and has been struggling to get that back in shape since.
Everyone knows kips and circles on mushroom take forever for some kids, and we have lived through that. I am used to the feeling of "my kid is never going to get this skill" and then, whammo, one day they get it and the struggle is forgotten. With this one it has been two years of "coach says I almost have it." I know it frustrates him and I admit it, me too! Luckily he has a great attitude and usually keeps these things in perspective.