Eh. If MyPy complains that I'm passing an `Optional[Entity]` into a method where only an `Entity` can go, it's just helped me avoid a runtime error when I try to get `entity.name`. Not sure what the exact PHP equivalent is, but there's all sorts of bugs you can easily introduce if you're not careful with types.
It is nice that you are trying to inform me but I am already aware of the information that you bring and your decision to bring it makes it seem to me as if you are uninformed. It is possible to conduct static analysis of a source code file that is not "compilation" in the sense that you would otherwise see with Java or C. Python's not really any different than PHP in this regard.
It may make it slightly slower