Addresses in a Craft Commerce 4 migration... wow these need better docs. Support ended up having me pull up the example template for the demo site and that finally helped.
Docs had bits n' pieces in different places and it's a where's Wally of frustrating. The template had a more complete picture of what needed to go into a frontend form.
Will be writing a blog post guide for future updates, it's not terrible if you have top level info and some syntax guidance.