Thanks for telling these anecdotes! Sign languages intrigue me, as their modality is so different. But when you actually look at it closer, you see how they’re not really all that different to phonetic languages. It’s mostly the interface that’s different. The concept behind it is the same.

My guess was that teaching a stuttering person a sign language could be a possible solution to overcome that psychological barrier since the way you produce communication is fundamentally different. If the subconscious can’t figure out how to stutter with hands, might it drop it when signing? Anyways, I do think that stuttering for native signers exists, as it seems only natural. I don’t think that phenomena is bound to articulatory-auditory languages. But maybe as a nonnative this might not be so intuitive…