There is a host at the top of the escalators. Trust me if someone is in the lobby that should not be they are asked nicely to leave (I promise you I have first hand experience of that delightful conversation), and the showers are controlled by the house keeping team and they are required to make checks before issuing shower suites to customers. If we put someone at the bottom as well as the one at the top and the staff on the desks I think customers may just feel a bit like they are trying to get into the bank of England!! We get more complaints around people feeling over processed than we do about people feeling that there are others in the lounge or lounge areas who should not be.