I agree with you. I used to stutter the most at work and on the phone. But as you said, I’ve met PWS who stuttered more with their family, or with certain friends, or who stutter more in their mother language.
In order to solve it, I took those harder situations as a challenge, as a game, and I challenged myself to speak fluently in those situations by using even more the Crutches, the only goal was to speak fluently. I succeeded and now I don’t view those situations as challenging anymore.