Advice for my 12 year old who stutters

Advice for my 12 year old who stutters My child has had a stutter since around the age of 3. It fluctuates often, and the phrases or sounds that are repeats repeats change very frequently, as it does for many people. He is EXTREMELY smart, kind, competent, amazing, funny, creative, Etc! He is truly a perfect kid in every way. He has completed a speech therapy program. Where the focus was not on fixing or getting rid of the stutter. But on understanding it. I try to make sure that he never feels like there is something wrong with him, because there isn’t. We have talked about it multiple times over the years, but it’s not something that I bring up because to me it’s not a big deal. I don’t want him to be fixated on it. I’ve always known that as he got older, and kids become more concerned with fitting in, that he would eventually face some degree of ridicule from his peers. He goes to a very small school, for now. But I worry about him in a new environment next year. My biggest fear is him choosing not to speak at all due to fear or anxiety surrounding stuttering. He is very observant. And I have witnessed him see the reactions on the faces of others as he speaks. Especially people who don’t know him well. People who can’t seem to hide their own discomfort as they listen to him, or even try to finish his sentences for him.. This REALLY bothers me! I know I can’t protect him from every painful experience in his life. And that I shouldn’t try to. My question is, looking back on your own adolescence, what actions on behalf of your parents did you feel helped or hindered you? If you could go back and talk to your younger self, what advice would you give? What was your own social experience at this age? How can I as a parent be helpful, without smothering? Should I continue to step back and allow him to navigate through these things on his own? I just want him to feel confident and proud of himself.