I'm toying with the idea of making this a multi-POV novel. I have an idea for a sequel to Mysterious Paris that works best as multi-POV, which is another reason for doing multi-POV (not just the benefit of extra scenes). Plus, Thierry is facing similar issues as Manon, and has drama from the start (if you know what happening with him).
Maybe during "the big revision" I'll make a list of new scenes to add, as I come across spots to add those scenes. Then, when I get to the end of the book, I can make decisions on whether to write the scenes.