>> little help popup telling me places I can go. I really appreciate this because I don’t often use the “go to definition” or “go to reference” feature and I often forget the keyboard shortcut.

> Exactly! Pity this basic contextual help isn't more widespread, every single app that uses a lot of keybind sequences could benefit from it, especially if it becomes a bit smarter and only shows a popup if you don't finish the sequence right away

I agree 100%. This would be helpful in so many places. That was my favorite part of the article -- one little paragraph and screenshot, but it made me desperately crave that feature almost everywhere. I agree that it'd need to be smart about it -- after a timeout, as you mentioned, is a great idea. That way it can stay out of your way if you know what you're doing, and only pop up when you hesitate.