Mom of teenage mild stutterer / blocker (M/17) trying to help and not make things worse

Mom of teenage mild stutterer / blocker (M/17) trying to help and not make things worse Hello! I have found other Reddit communities helpful for other purposes and am hopeful of finding a supportive community here as well: my son is now 17 and is a twin who was born prematurely and has stuttered mildly on and off since he started talking. His twin brother was the “Baby A” dominate twin and started verbalizing first, so he would often finish his brother’s sentences for him when he would stutter or pause. We used to think it was cute and my son with the stutter didn’t seem to mind the help when he was little. As he grew up, his stutter would come and go and didn’t seem to bother him too much. He would sometimes freeze and block with certain consonant sounds like “D” and “T” and unfortunately “J,” which is the first letter of his name. He had a few instances of kids teasing him when he was growing up and was the one to say that the kids were “jerks” and it didn’t really matter to him, since he didn’t care what they thought. At various times over the years we have talked casually about speech therapy - none of his pediatricians thought that the issue warranted that approach and he himself had maintained that he didn’t really want or need it, since it would cut into sports practice times and fun with friends. Flash forward to now, when he is preparing to leave home for college. He has asked me to help him find someone to help or some other resources he can use on his own. I have already emailed his regular therapist to see if she has a referral (he did ask her about it during their sessions and while she did say that it was interesting, as it is transient and not specifically triggered by stressful situations, she said she could not help address it as it is not her specialty). One time that it seems to come up regularly is when he is ordering food while out at a restaurant or fast food drive through - I have read many posts here and that seems to be a common trigger. Often times he will ask me or his twin brother to order for him. Since he is preparing to live away from us later this year, I am thinking he wants to be ready to do this on his own. Basically, I am reaching out to see if anyone has any helpful books or videos or other resources they would recommend to a 17 year old boy. Also any tips for me as his mom. I want to do everything I can to help and of course not do anything to make him feel bad or stress him out (which is becoming more challenging during the teenage years). Both his father and I are very rapid speakers, so I am really focusing on slowing down my speech and giving him plenty of time to respond when I asked questions. If anyone would be willing to share any tips on things that their family members / friends / significant others did that helped and likewise things that didn’t, I would be very grateful. Thank you for taking the time to read my post - I really appreciate it. Seeing the support given and received in this community has been heartwarming and gives me faith that my son will find a supportive group when he is away at college later this year, which is something we both really want.