Makes me wonder if stepping back and thinking, instead, about a way to automatically (optionally?) put the current calling context dictionary(ies) somewhere that a called function can get at it/them, so it can do what it wants with the context.

I think that would violate the expectation that a function call means the same thing in different contexts, hence f-strings work by supplying values at the "call site" not variables. I know you will find exceptions (like import context), but they are not as all-consuming as snapping the entire namespace. If you really want to, there's sys._getframe.

Jeff