Autochoose for press and hold? Is there a way to change the press and hold character picker in a way that it automatically choose a certain character.

I'm German using an US keyboard (on purpose, I don't want to switch back to a German one) and if I press and hold 'a' I get a lot of options. I don't care about any of them but the 'ä'. I know how to eliminate the other choices (thanks to How to add characters to the press and hold character picker in OS X Lion?) but I don't even want to chose. I want to hold and press the 'a' and would love for the 'ä' to just appear without me having to choose it.
I don't think you can do this with press and hold, but you can press:   option + "u" then "a" to get "ä". I find it quicker than pressing and holding the key.