We got tired of not being able to install our mods on Matrix/Matrix 2 controller boards, so we did something about!!!
The Matrix Expansion board is a separate piece of hardware that sits in between the controller and your mod chip to add support to allow the mod to control the (2) buttons on the controller.
It's very small (about 1/2" x 1/2") and very inexpensive!!!
Installation is only slightly more complex. Instead of running a wire from the mod to the button you want to control, you run that same wire to this board, then there are two connections that go from the Expansion board to both sides of the button. You do this twice (once for each button you want to control).
This kit comes with the Expansion Board and 2 feet of 30 AWG Kynar wire.