Just to confirm what other folks are saying:

I had the "book at regular rate, adjust as checkout" done this past Saturday at the Borg at the recommendation of the room manager. They said that the front desk doesn't usually check to see if the room was booked at the poker rate, but they will usually call down to the poker room to verify that you played. They also adjusted the room rate directly from the podium on recent Monday night one time. Not sure why they didn't adjust the rate from the podium for the Sat night stay - maybe different folks have different understandings or responsibilities.