I'm not sure what you mean by "around this." There's not much you can do if you want to see providers who tour. Sometimes they book hotels with key elevators, sometimes not. You could take it upon yourself to book a room at a hotel you know doesn't have key elevators. Locals generally provide at their home or share an apartment just for bookings with others. Major city hotels frequently have key elevators, just the way it is. Incalls in the suburbs or more rural areas tend to not.
As for ways to get around the key issue discreetly, if they're remotely organized just follow their lead. They will guide you someplace to meet discreetly and you head up together - like the floor of the restaurant/bar, the conference room floor, the area by the elevators, lounge, wherever. They're the ones who have to meet multiple clients so they've put in a lot more thought into it than you have lol. Ask them for directions around the lobby so you don't look lost. Most of the time I'm directed to some area away from the front desk. A few times the provider arranged to come around the corner outside the hotel and handed me a key and asked I wait 5 minutes before heading up.
It's not really a big deal. Corporate has to put out statements against it but they know a lot of their revenue in non-convention times come from escorts. As long as no one is making a scene they're not going to do anything. Generally just don't hang around inside the hotel. If you have to wait, wait outside out of sight then follow their directions to the meet.
