Are the four characteristics -- production, abiding, change and destruction -- empty, conceptual constructions?

Are the four characteristics -- production, abiding, change and destruction -- empty, conceptual constructions? Does this make production etc., perhaps even impermanence, an illusion, especially according to hua-yen Buddhism [as that's where I've seen these four characteristic enumerated]? ---------- I do not think this is a mere "metaphysical" question in the pejorative, because it may say something about birth and death: whether or not samsara -- karmic conditioning -- and so nirvana -- its termination -- are empty of essence; what the nature of first and third noble truths are.