Hi, currently booked BOS-DFW-LAX-HKG-KUL in F for mid-May 2014. Does AA ever open up saver F on the JFK-LAX route, and if so, when should I be looking for it?

On a different note, if one is on an saver F award (or J), but wants to switch a segment to Y which is only available at the anytime rate, does the total price increase? Not expecting that to happen, but just got to thinking.