Perhaps you're right. Perhaps not. There's plenty of data already. Plenty. It's just not in the public domain. And won't be. Ever.
Going back to my point, Sprey uses his love of Apples to say that an Orange doesn't do what an Apple does. This is the rudiment of his argument every time he's wheeled out as a talking head and it's the concept and doctrinal part I'm referring to, not the reality (or otherwise) of what F-35 can do today, or may do in future. Like having your grandpa tell you that you still need horses on the modern battlefield.