I’ve found sketchy styles to be immensely useful in getting clients to focus on UX and structure rather than getting stuck on minor irrelevant details. My background is construction, and architects do the same thing with initial concepts.

Yep, it's super common that when you show a UX prototype to a client they'll hyperfocus on things you don't want them to focus on right now like the font choice or button colors. Making it look rough and muted can help.

I never thought of it that way, that makes sense.