I do sometimes, to kids I know well, in a formality-as-affection way.* I grew up calling adults Mr./Mrs/Miss. Last Name (for people I did not know well) and usually Aunt/Uncle First Name for non-related adults who were family friends. I think in my head Ms is an adult term, I've never really thought about it. Some of my friends refer to me and Justin and Miss/Mister to their kids, and sometimes Aunt/Uncle (actually, he's Uncle Ding0, an old burner nickname that has stuck around).

I'm from MD, as is my mom, and my dad's from VT. Most of the family and friends we spent time with growing up were from MD or the South.

* I do the same thing to animals, too, so it could be just a me thing.