Python-friendly return of 3-element vector from VTK class

Yes, that sounds like a good way to handle std::optional<T>. The Python user would only ever see a T or None, because the wrappers would automatically do the has_value() check for the benefit of the user.

I’m in agreement with Ben regarding T*. Returned pointers are horridly ambiguous from C++, and can only be handled nicely in Python via an abundance of hints.