It's good to know that the matrix is necessary, anyway
I probably should have just given up on getting this push button to work, but I have this problem where once I see the potential for something, I can't quite give up until I get it :P
Did you mean it isn't necessary ? or maybe i wasn't clear? you don't need a matrix if you have enough pins available to wire each switch (button) direct , which you may have if all you are wiring is this one thumbstick and a few extra buttons...
KB
Some Images from the Original MMjoy16 Instructions and the pages they came from....