There are many contradictory theories about Age-Uké: Kanazawa extends the "preparation" arm fully (which is the actual block actually!). Then, Funakoshi said in his first book (Rentan Goshin), that the wrist position should be at the center line. And then, application wise, many say, the final movement is not a block but a strike to the neck of your opponent, so it being only one fist apart from the forehead becomes nonsense. This confusion comes from Kobudo where you hold a weapon in your hand, and so the Age-Uké really becomes a block (Against a downthrust with a Bo for example), and needs to be close to the forehead, with your elbow being over your shoulder, and the wrist not in the center line anymore.