It's not just that Red has two lives to Frank's one. Red has two distinct lives, as different from each other as almost humanly possible. It's not even something that Frank can wrap his head around - he's never been anything as much as he's been dug into being himself, the sum of his own parts.

"Is there a real for you when you're not in the suit?" Question's mild, honest, not asked to start a fight or pass judgement. "Yeah, you got your reasons, but doesn't that just mean you're making it easier on other people? You talk about fakin' it. You doing it for them? Burning yourself out for them?

"Maybe it would take just as much work to do it the other way. But you wouldn't be fake."

He's not suggesting Red live as the Devil. But he's thinking that Red maintains that helplessness so that the Devil can survive.