Yeah, that driver is the reason I had ordered a used Mac laptop, though at this point I probably won't need it.
From what people have experienced, my theory is that the Mac driver only has chatpad support with the 360 default USB wired controllers, and not the "made for Windows" wired controllers. I think, HOPEFULLY, I know why.
Also, as far as I know that Mac driver does not support wireless controllers at all. I don't have a wireless controller or receiver, so unless someone loans me one or buys me one, I may not spend much time trying to add chatpad support for that.