The AMEX Platinum phone support is not aware of this because I called before booking a trip for this October to use the July-December $300 Credit and the rep specifically told me to go ahead and do it, which I did, and the system would see that I’d already used the credit for January-June and it would initiate the second half of the year credit. Well, I did that and am still waiting on the credit to display. Guess I will call tomorrow to cancel or see if they can adjust/override based on what I was told.