At the moment I am waiting for my phone to be shipped, when it comes in I will:

-make a very simple dock to easily connect i2c pins
-hook up the TCA8424 in its evalution module (no need for a pcb) and see what happens
-ask for help on the software-side to make this proof-of-concept work
-program custom keyboard layout in the chip
-design and order custom pcb's
-make new OH with keyboard-casing
-be awesome

Currently I am about 100 euros in and that figure will increase when I am at the point to order pcb's. I wouldn't mind at all if people would support me money-wise, but I can not make any promises regarding building keyboards for anyone else.

What I can and will do however, is share everything I draw, make, order whatever. A lot of openness so to speak. A successful outcome would be an semi-idiot-proof instructions to create your own.