This key should only be used on a test installation that you download with the links from the opening post. Using it in any other way will result in a lot of unforeseen consequences.
- If you use this key and upgrade a test copy of your store, you’ll most likely end up with the old 4.18.1 Beta.
- If you use it in your live store, it will break the store later on. To a point that even our Customer Care might not be able to help.
P.S. Thank you for bringing this up. I’ve added an explicit warning not to use this test key in a live store (just like in the Beta article).