Ah yeah, didn't remember that constraint in Python. I thought I read something about a future version fixing that when it comes to just type hints, but I suppose that wouldn't work here, since it's not really a type hint, right?
Yup, you're thinking of "postponed evaluation of annotations", which is currently optional with `from __future__ import annotations`. But as you said, would not fix the circular import here.
Those classes can reference the settings, so including them as strings is done to allow that to work without creating circular imports.