Personally, I wouldn’t want to add the note into the mentioned tutorials, as they are working fine in the current state. In my opinion there are a lot of edge cases, where just copy pasting the tutorial might not work out of the box and I don’t see a custom sampler as the usual use case.
That being said, I think your suggestion would fit into the FAQ section.
Feel free to create an issue on GitHub and explain your proposal there, please.