In the future keyboard designers should make the protocol more configurable so that on casual observation it is not so easy to determine what packets are data
Thats a very common misconception, but the fact is that is pretty exactly what they should NOT do.
Specifically that is, they should not even attempt to design their own method of securing the data. They should use fairly standard, well tested, modules produced by professional cryptographers. Full stop. These are solved problems, and there are several very well researched and well designed techniques for solving these issues.
There is always room for more such techniques but, to think that some engineer working on a keyboard is going to design one that is even as good as what we have as just....a submodule of his project is just not realistic.
Choose a solution for authentication/key negotiation....choose a cipher. Go back to designing the keyboard itself. That really is the best part.... since its a solved problem.... it really isn't a huge level of effort to fix correctly.
Plus its a keyboard...a "pairing" could be as simple as flipping a switch into pairing mode, then typing some text that shows on the screen of the device pairing with it. Its not like its some headset with only 2 buttons.