I guess I'm still confused. In Safari (for example), command+[ corresponds to Back and command+] to Forward. If I want to use just a single keypress for Back, I can use the method in my previous post to bind Back to the left-arrow key (for example). Then I can simply press that left-arrow key to go back, instead of pressing command+[. (A function key could be used instead of the left-arrow.) These modifications work for me, but maybe I'm still misunderstanding what you want.