People spout off all kinds of nonsense about construction hoping other people will just accept it because they don’t know. Whether or not it is a custom design is not something that is going to be easily deduced by photos or even construction methods. Being steel doesn’t mean it’s custom design. Being prefab doesn’t mean it’s not a custom design. The Contemporary Resort and original longhouses of the Polynesian Village are both custom designs that famously used not just pre-fabrication of parts but entire rooms. Galaxy’s Edge had a goal of as much as possible of “design once, build twice”, so essentially pre-designed for Florida but also very unique.
The gift shop has also been misidentified as a pre-engineered metal building. Those types of buildings are giant kits but they’re not really pre-designed. They’re also the type of structure used on The Amazing Adventures of Spider-Man and Harry Potter and the Forbidden Journey, both considered amongst the best attractions in the world.
There are people who just spit out and double down on things because they fit the desired feeling they want, to criticize or praise Disney. There is no inherent value to using certain systems and methods. There are valid use cases for pre-designed and pre-fabricated elements. Even if this was a pre-designed manufactured building, that in and of itself is not the problem with it.
