Brace and Liz need to smarten up their infiltration game. Any gumshoe should own disguises, not necessarily to make you look like a different person as you approach the normal entrance, but to look like your allowed through the back. You can just buy security guard uniforms from people that had that job, I got mine from a thrift store. Get a dress shirt and a vaguely red vest and you're hotel staff. Wear a high vis and have a dolley full of boxes and say you're with Sysco. The best way past for surveillance purposes is just to be 'with somebody'.