I think http://caniuse.com handles this situation quite well (try searching for something). Notice the short delay between a keypress and the URL updating.
They reset the timout everytime you type another letter. That approach seems to work quite well, unless you are a very slow typer.
However I have just implemented another approach to deal with that issue. Now, the history is updated either when the current field lost focus or when you move the mouse, after you entered something. Please try it out and let me know what you think.
However I have just implemented another approach to deal with that issue. Now, the history is updated either when the current field lost focus or when you move the mouse, after you entered something. Please try it out and let me know what you think.