Yes, it's a tradeoff as to which plot line is the dominant one of the Season. You can wrap up your B plot in the penultimate episode, but your primary plot is saved for the finale. Surprising no one, I have a preference for the Feanorean plot line, and prioritize appropriately. That, and Morgoth is the primary antagonist, so the issue he is playing an active role in has to be in Episode 13. Some of the other items can shift (Eol can be in 12 or 13, wherever he fits best.) But Morgoth interrogating Maedhros? That has to go in 13. He'll be stapled to the cliff before the Sun rises, and we *will* show his reaction to that. But as for maintaining any particular timeline between the rising of the Moon and the rising of the Sun. . .the audience isn't going to be given many clues about how long the gap is.