It should update whenever you press Apply. Try running the game in window mode when updating to see if that helps, but admittedly this hasn't been tested in some time.
In the future there will be a new way to adjust the positions of the overlay which I think everyone will like quite a bit more.
There currently is no way to alter that through the options we have exposed. I (and others) have wanted that functionality for custom voice packs and we plan to allow it. I'd like to come up with something that allows all achievements to play dynamic sounds with their own rules.
Thanks! We put a lot of work into it and have a lot more updates coming.