I have but only non speaking/minimal speaking parts, or parts in musicals, as singing isn't an issue for me. I would usually change a lot of my lines to avoid problem sounds and words. I've still had a handful of embarrassing moments of blocking badly and people thinking I forgot my part, but for some weird reason just having that excuse makes it feel less embarrassing. I have definitely also found it to be true that when acting and speaking in an accent I stutter less, and being in plays has actually always been a lot of fun for me for that reason. It's nice to be able to participate in something for once.