I am continually astounded by the stubborn incuriosity of humans with a bone to pick.

What in the world are you talking about. Please specify how lack of types helped you in your aforementioned scenario.

I don't think it's a lack of curiosity from others. But it's more like fundamental lack of knowledge from you. Let's hear it. What is it are you actually talking about? Testing a subset of a library halfway though a refactor? How does a lack of types help with that?