Can I downgrade to iOS 11?

Episode 1540 (40:52)

Marshall from Des Moines, IA
iOS 11

Marshall wants to know if he can downgrade to iOS 11. He doesn't like 12. Leo says he can, but he'll have to erase the entire iPad. It's also only possible to do this for a limited time, and that window may have passed. iMore has an article that shows to do it here.

But that chatroom shared a link to that says the time to downgrade has already passed.