This will be a short suggestion centered around the Lobby vending machines.
First of, the soda machines. I think they could use a new model representing their new stock (soda cans instead of Zelda-esk bottles and… Half-life 2 water cans?) and some more soda flavors to pick from.
The food vending machines should be usable and players should be able to place down and eat their items just like the already purchasable pizza.
As for the SWYP machines… I can’t think of a proper use for them. Using them to join other lobbies/disconnect from the game would be cool, but I can’t think of anything else.