I recently had a three night stay and opted for the MAGC at check-in. And like clockwork, I woke up during the night around 3 AM to notice my vouchers were indeed received. Funny thing is that on day 3 housekeeping cleaned my room at some point that day (I was always leaving the property around 6 AM and returned each night after midnight.)

I left the two vouchers on the table near the door as a reminder to myself to redeem them or turn them in at checkout. At checkout I turned them in and had no issues at all. I just found it strange that they cleaned the room. I understand that sometime they "check" if the room is really being occupied for whatever reason(s).