When your search about Staingate on the internet, you will find many articles but most of the content is not useful. All of them talk about “what is the staingate” and how it appears but not about how to prevent Staingate. It’s so easy.
After 2015, Apple used a special anti reflection coating layer on their Retina Screens. This layer is too sensitive and gets unstable under Temperature change, so to prevent damaging this layer, follow the below description.