I'm wondering if someone could make a small mod that relocated Serana's "Home" location to Valerica's Castle Volkihar lab or to the courtyard if the player sided with the dawnguard and went back to the soul cairn to bring Valerica back. It doesn't make sense to me that Serana chooses to stay with the Dawnguard at the fort if the player goes back to the Soul Cairn to retrieve Serana's Mother.