So I am currently on the Hyatt EXP challenge (same requirements as this one) and just wanted to see if anyone had a confirming data point. I emailed and got assurance that a JL operated/marketed flight qualifies; my intention is to use the Amex IAP program to buy the ticket, which will save about 10% and all segments book into X. There isn’t some strange quirk of the IAP program that would invalidate challenge earnings is there?