I currently ignore the right click button, does not pass it to MacOS, and do not enable ps2 intellimouse features (such as all the extra buttons, scroll wheel, etc). It could do something with it, but 1) pre-ADB has no way to pass a second button, since the mouse button is a switch on a wire, and there's no second wire, 2) I'll just focus on getting existing functionality working well, I think.