“This is what PAA refuses to acknowledge. He thinks if something was ever not-K’firah, then it has to remain not-K’firah L’olam Va’ed”
It depends what you mean by that. I definitely say that the objective truth of any of the matters can never change. If you just mean that something can become labeled as kefira even though it might not be kefira then I might agree somewhat (see my past posts).