Highlight state of three-button buttons

A recent thread here about toggling the button icon highlight state in certain ifset conditions reminded me that it would be preferable for three-button buttons to have better icon state indication as well.

For instance, I have a three-button button where Left, Right, Middle clicks do different types of flatview modes... Only the Left Mouse button state is reflected by the button change in icon status. Has this ever come up before and been rejected for some reason? I vaguely recall some bit of dialog around this but can't find the thread if it did...