So it seems like what I initially said about the Adafruit RGB button not working with RGB Strip mainboard headers was incorrect. They both use common anode, so there's no reason for me to try and replicate what they are already selling for a good price. You'd have to add a resistor so it works with 12V, but that's a simple mod to do.
That makes it more interesting. I'd love to work on compatibility with NZXT, but for now that's not a priority. It's a cool thought, though. Animations would then be colour-less and the colour would just be whatever the Hue+ sets it to be. As the firmware will be open source, NZXT could also easily implement that part themselves if they wanted to.