I'd just like to mention that your preferred convention of surrounding key sequences with braces is perfectly reasonable on its own, but it's unlike any other GNU Emacs (or GNU in general) documentation. (Which is why Texinfo doesn't support it directly.)
If hyperbole users are most likely not reading anything else, that's fine, but if they might be looking at the Emacs (or Info or ...) documentation, it seems like it could be rather confusing. As in wondering why hyperbole's key sequences are always surrounded by braces, does that make them different from Emacs key sequences, if they're supposed to type the braces, etc. Just a thought FWIW ... -k
