You mean like using that argument on Rinny? Hmm, that could be a way to talk her down I suppose. And yeah, there are a couple things that'll change from having true succubus/incubus status.
Viewing post in Rinny's motivations during her second route comments
Either talk her down, or persuade the queen. i personally think the line of "There are people that love and need me, like your subjects love and need you, I cant abandon them, and when i was brought here it wasnt with the knowledge that it would be for eternity." would be at the least enough to make her second guess her own assumptions of the mc.