Thanks for the comment! Important question, I'll answer my opinion. I think it's an healthy habbit, therefore I'm suggesting making this an habbit by adding type annotation to every place you can. I'm agreeing that the complex structures are more dangerous, but as we know we cannot slight any piece of code, even the simple ones, the more you annotate your code, the more coverage and protection you gain.

A very interesting topic that can extremely optimize flows! Great suggestion, thanks!