I have worked on sweat crews. They probably used the metal park service lock box and bear cables.Most of the shelters in the Smokies have a bench and a high "table" running across the front of the shelter, which is what I used to cook on. I would say, out of courtesy, don't bring any food or drink other than water on to the sleeping platform. This summer, I had a guy spill a sugary Bailey's and coffee drink on my sleeping bag that he was drinking on the platform above me. It was not cool.
That said, even though most people are trained not to eat near where you sleep, most people I have encountered out there find it acceptable to cook around the shelter on the benches provided for cooking. Among hikers, the attitudes about keeping "smellables" out of the shelter range from "meh" to crazy strict... I stayed at a shelter with one guy who was an Army Ranger and used his food bag as a pillow, because he said if anything tried to get his food in the night, he would just "defend" his food. And there were great thuds and cursing in the night as the shelter mice breached his defenses... hahaha
On the strict side, in the Smokies this summer I was stopped at a shelter for my afternoon "cocktail" (3 ibuprofren and a cup of coffee) and was sitting on the inside bench at the table at the front of the shelter, having nice chat with some other hikers about native plants. Up walks a woman who is a paid guide for REI... she loudly proclaims that pack hangers attract bears, and cuts all the pack hangers down, even after I told her I was pretty sure the ATC sweat crew that was camped there was using them. She then announces to the women she's leading that it's ok to cook at the outside bench in front of the shelter, but not at the inside bench (which is maybe 2 feet closer to the shelter than the other bench). Since I was heating my coffee water on the "forbidden" bench, she directed her attention to me, and started giving me a lecture on Leave No Trace. I just laughed, packed up, and moved on, but I felt sorry for all the people who had to stay at the shelter that night and get "educated."
Sorry if this is too long, I have a story for everything! Just cook on the bench out front or by the firepit on a flat rock and you're fine--have a great hike!