Supreme has always had a reputation for being warm and welcoming, so I'm sure it's fine.
Some years back I was skating LES, finished the session and went over to Supreme to grab a hat and a hoodie. Employee was super disrespectful to the few hypebeast types floating around the store. As he approached me I was bracing for impact after hearing the way he was talking to dudes in there. Not sure if it's cause I had my board with me or what but he was super pleasant to me, explained their whole we only keep one of a thing on the rack if I need something they'll grab it from the back. Talked about skating for a few minutes. When I checked out he threw in a ton of box logo stickers, way more than the standard 1 or 2 they usually do. For what it's worth I would probably be burnt out after dealing with thousands of hypebeasts a day too, and would for sure talk shit to them cause they're still gonna buy the shit.
With this knowledge I would say you'll have to know someone or be someone to get a session in.