Hope this post of mine from last year helps:
PrincipalTinker
Hey, we just got back from our trip. I am not sure if this helps you, but here is what we did… We booked FoP, EE, and DINOSAUR back to back in the AM for AK in advance of our trip. After scanning into FoP, we attempted to modify DINOSAUR so that we could look at availability at MK. The normal warnings did not pop up, the system simply would not allow us to get past by “Continuing” with each guest. Not sure why, or if we did something wrong. I also attempted to get through the “ Add a FP ” process and same thing. We were blocked and could not bypass. However, I took a chance and just deleted my DINOSAUR FP, then went through the “ Add ” process and selected MK. The system allowed me to add an MK FP, even though I was still holding EE. The result was that I was holding EE and Winnie the Pooh in MDE at the same time.
So, (at least last year this worked for us) I think once you are in AK, after you scan in to your first preselected FP, you can delete the AK FP that you don’t want, and select a FP in Epcot for later in the day.