I know I have like 3 asks in your inbox by now, but I'm just so incredibly curious about your characters and whatnot. I'm not sure if flooding your asks like this is annoying at all. If so, my greatest apologies. I know you've said that your accent is a mix of many and that certain characters require different things, but I'd like to know more about Mouthpiece's voice in particular? It's one of the things that immediately drew me to their character in specific!
The voice of mouthpiece changed over time; at first, they did not speak at all; then, they spoke in fragmented words, on both exhale and inhale. After enough has passed, they started being able to speak properly, but their speech remained erratically paced owing to only ever speaking 'carefully' - outside of the Augur encounter. And then there's the sibilance, of course, but that one goes without mention.
If a character speaks with characteristic 'stops', that usually entails that they're choosing their words carefully - Mouthpiece did so quite a lot; the Augur, in turn, may turn out to be more fond of running quickly, and backtracking when need be.