@Mike-HubGit would this have helped?

for users like me I am not sure : in my mind a code example is far more striking than a comment somewhere. It is perhaps only my own preference, but what would have helped me would be a 3rd annotation using for example axes fraction coordinates (like in the suggestions I sent, but not to replace the "display" coordinates). This is for a single reason : a user of the library works in a more global code. If he has an example he will copy/paste it simply, and use what works for him, even if he doesn't have the knowledge of the underlying concepts of Matplotlib. And yes above this a comment that says that this is the most stable way to work.

This is perhaps only my way of thinking but : Matplotlib users are, I think, for most of them, general purpose scientists and not computer-science specialists. In their learning curve, the first code they want to use is a code that simply works. In a second step, if required, they will investigate better what'ss inside Matplotlib.

Thanks @Mike-HubGit. I think its important to bear in mind that the tutorials are longer form narratives and need some freedom to tell their own story versus provide self-contained examples.