Sigh. my noobius maximus in code is showing... I'll somehow adopt your code to the teensy, one day.
I've wanted an official page for documentation for a while, and I think ReadTheDocs is perfect. I can update everything easily though GitHub and I don't have to waste my time trying to make it look clean and simple, so I can spend more time writing documentation. Check it out here! http://docs.thnikk.moe/
With the code I've written for the macro keypad (the 4K too), I think I'm getting much better at writing clean and concise code. Since all of my keypads use the same microcontroller, there's no reason that I couldn't go back and add this serial remapper to all of the other models. While I'm at it, I may rewrite all of the code or edit it if it's simple enough.