Yep, in dealing with a fair-sized Python 3.8 codebase, type annotations with "Optional [...]" (nullable) and "Tuple[..]" (multivalue) coupled with a static type

Yep, in dealing with a fair-sized Python 3.8 codebase, type annotations with "Optional [...]" (nullable) and "Tuple[..]" (multivalue) coupled with a static type checker (in PyCharm) has been enough to mitigate the worst kinds of type errors.