I can't see to find the answer to what happens if I fly the outbound of an award flight and need to change the return. The chart shows no fee for 1K members but reads as if that applies only to the entire itinerary (i.e., before you start the trip).

Also, can I decide to take advantage of the Excursion Perk after flying the outbound portion? For some context, I am flying DEN-NRT then NRT-DEN and may need to change the return to NRT-YOK then YOK-DEN after I get to Tokyo.

Thanks.