For those driving cars,
I will say, if you are really worried about it, mobile order a soda(or something cheap) from the resort quick service before you get to the security gate and just say you are getting a food order that you already purchased. You can show them the order screen and everything if they ask. That's the (to this point) foolproof strategy we have to park at any resort whenever you want. Even Contemporary before fireworks time.
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Granted, as others have said, you generally can just roll up and get in no issue whenever you want. Especially when you mention something like "we are going to Abracadabar" at the boardwalk or something. Places that are not predominately or at all reservations based (bars and lounges) are a great excuse.
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Getting back to the Mobile Order thing,, unless the security wants to deny you purchasing/picking up your order, they kinda have to let you in. And $5 or less for the peace of mind can be worth it situationally.
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(We usually do this at Saratoga to get into Disney springs when the garages are full, most common use for us)