Good to know re: award tickets not qualifying for free STPC; have already arranged the nearby Grand Hyatt at a reasonably low price (~400 QAR), so happy to proceed with that.

One thought though - to your point @Unionruler - how does my booking flout the criteria re: "there should be no immediate connection available between Qatar Airways to Qatar Airways flights on the date of departure from origin"? Once I land at ~10 PM local time, I believe the soonest possible onward flight to Madrid is the ~7:25 AM one, so this is the shortest possible connection on two Qatar tickets, no?