Advice for best helping my son (11 yr old)

Advice for best helping my son (11 yr old) I've been reading through this reddit for the last few hours and wanted to ask for advice on how to help my 11 year old son with his stutter.  His stutter started ±1 - 1.5 years ago, and i can't recall any major instances of stuttering earlier in life, maybe short bouts lasting a week or two when he was learning to talk (he is bilingual).   Since it has started it started with a minor stutter which got progressively more noticeable and he asked himself to go to a speech therapist so we found one that was highly recommended.  He went for ±6 months until she took maternity leave and it did seem to help somewhat, but it still came back, and I didn't feel like there was any major progress done, though he enjoyed it.  She gave him a number of exercises to do (having him explain rules of a game to her), but aside from his stutter he has the tendency to explain things in a less coherent way so the focus was both on that and less on his stutter.  For example, if asking him a yes/no question he can sometimes start explaining background information that isn't really relevant to the question and it's hard to understand his bottom line.  This existed before his stutter became more noticeable, but obviosuly with a stutter it makes it more difficult to get his point across. My wife and I are very supportive and don't make a big deal of his stutter - initially we made the mistake of suggesting tools (e.g. deep breaths, slow down, etc.) but have stopped doing that unless we can see he is agitated by something, though that's more advice for calming him down in so he can speak coherently and less to combat the stutter.  He has his group of friends and is a very intelligent child, reading tons of books (he finished the entire Harry Potter series 3 times), is imaginative, and even participates in class quite a bit which makes me very proud - I was extremely shy as a kid and here he is not only participating but doing so with a stutter.  While I don't want to bring negative attention to the stutter I know that it does frustrate him (when in a bad stutter his body will tense and he'll sometimes make a swinging motion with arms to try to "get it out"), though he has managed to keep humour about  it - I remember a few weeks ago he had a really bad stutter and started smiling/laughing at what was happening.  I'd like to suggest to him some exercises to try and do to help in some way -  I've read a few exercises that could help, such as reading out loud for 10 minutes a day, taking a deep breath when he finds himself in a bad bout of stuttering, but I was wondering if there are other things that have helped people in this community. Another interesting note - he seems to stutter a lot worse around my wife and I; I've observed him playing with friends or chatting on discord/phone with friends while playing and he stutters a lot less.  He does seem to be more stressed around us that causes the stutter to happen more, and we're trying to work with him on this (to be less stressed around us I mean).   Any advice would be much appreciated