This is hard to answer, because not only am I a stutterer, but I work in publishing! Because of that, I know that to sell a book with a stutterer as a MC, you need to make it marketable to people who don't stutter. They're the vast majority of the book-buying populace. And they don't really care about stuttering. They don't understand it and they don't want to read the intricacies of how it effects our daily lives. Even books with, for example, trans issues are largely going to gloss over a lot of really in-depth stuff. So it needs to be delivered in a way that fluent speakers can still relate to the character and project their own wish fulfillment on them. The stuttering side of me thinks that I'd personally appreciate either approach. I'd consume any media where a stuttering character is featured. But again, I'm not your market. Stutterers can't be your market. That's how you only sell 15 copies, lol. In any case I don't personally feel like "MC just happens to have a realistically-depicted stutter" is in any way minimizing stuttering. That's just how we are. There's no great origin story for our stutters. They're as 'meh' as our eye color. The cards just fell that way. So were you to write [literally any story] + [character happens to stutter], then that'd be just fine. I'd just advise a complementary characterization. That doesn't even need to mean 'isolated, introverted, very internal thinker'. On the contrary, I'd love to read about an energized, extroverted, happy stutterer more than someone like I was in high school.