At what point does something move from being a cheat-sheet to being a reference manual/training document? I don't have a hard definition other than the "you know it when you see it" and this cross that threshold for me.

A cheat-sheet I really like is https://devhints.io/bash which I feel has just enough info (for me) when jumping back into bash from other work to give me proper context.

For me the threshold is in the name: a cheat sheet must fit on 1-2 sheets of paper that you can stick to a wall or keep on desk without forming a pile. If it doesn't fit on paper it isn't a cheat sheet it is a reference. You can roughly apply the same guideline even digital format a chat sheet must fit 1-2 screens without scrolling.

I have nothing against references or this website as a reference those are useful as well. There is a value in having a good reference which strikes a balance of being exhaustive while avoiding the trap of unreadable verbosity that specifications and standards often have.