Firstly, this is one of the best posts I've heard about what I hear is parent is doing so wonderful job, you deserve some credit. Now to your son. If you live in the US, my single best advice would be to get him involved with FRIENDS and/or Camp SAY. They are both wonderful organizations centered around kids his age where he can meet other kids who stutter, make new friends, learn from role models, and not have to worry about his stutter. They are both stuttering affirming and I think the best thing you can do to help his self esteem. Friends has conferences and Camp Say is well, a camp. https://www.friendswhostutter.org/ https://www.campsay.org/