Originally Posted by
Cledaybuck
I don't really understand what you are saying, but I will take your word for it.
It looks like they still have some bugs to work out. That first one in the screen shot should be an even exchange (and it is if you click on it). +10k is for F. The other two are correct for Y.
Say you have a booking JFK-LHR-ZRH in J, you've booked the last seat on the plane. You now want to change this flight to JFK-LHR-MUC. A "change" would let you keep your existing JFK-LHR and just change LHR-ZRH to LHR-MUC. A "cancel and rebook" would require existing inventory for JFK-LHR, so probably wouldn't show up in your change screen because it's currently sold out (since you booked the last seat).
If that makes sense.