I think you are being a little bit paranoid, and that keycard elevator thread is filled with paranoia. I also think it's naive to believe that hotel staff are oblivious to hotel hookups and will somehow be ruffled if they see you with an escort in your room.
Let me tell you a story from the summer of 2002. The time was July 4th weekend- Jazz Festival in Montreal. The place was the Delta Centreville (it no longer exists, but the rooftop of the hotel had a revolving restaurant at the time). It was located on University Avenue, now known as Robert Bourassa Boulevard.
I booked a 4 hour date with an escort from Allisa of Montreal. We went for dinner and then came back to the room. After a torrid hour of sex, both of us were laying naked on the bed. I was nude face down, she was nude face up, on top of the bedsheets. Full nudity. As we lay there, out of breath, we suddenly heard three fast knocks at the door. The knocks were in such rapid succession that I hardly had time to open my mouth and breathe, let alone speak any words. Before I could get off the bed, the doorknob twisted and the cleaning lady stepped into the room. Seeing me and the escort, both fully nude in the bed, she let out a low moan and then said "sorry! Sorry! Sorry!" After which she turned around and hurriedly closed the door, as if to unsee what she just saw. It was obvious she expected the room to be empty but instead, much to her shock and unwitting voyeurism, she found out otherwise.
The next day when my room was cleaned I found on the bed some extra chocolates.




I didn't see the voyeur cleaning lady again, but if I did I would have thanked her as the chocolates were superb. This was back in the day when hotels actually did cherish their guests and give them complimentary treats. I left a $20 bill on the dresser as tip at the end of my stay.
Moral of the story: you don't need to be in the lobby to be recognized by hotel staff as being with an escort. Can happen any time anywhere.