I recently realized that New Moon is the only book that hasn't gotten a second perspective. Twilight got Midnight Sun, Eclipse got The Short Second Life of Bree Tanner, and Breaking Dawn technically got Jacobs perspective in the middle of the book.
I think it would be really cool if we got one. Jacobs perspective of New Moon would be the most interesting I think. Seeing Bella go through her breakup and also his experience of becoming a werewolf. I know Midnight Sun mentions a bit from New Moon but Edward's perspective is kinda boring honestly, like the 10 pages of his inner rambling of how much he disliked Bella.
In Breaking Dawn, I originally skipped Jacobs part because I thought the start was boring but when I was done I wanted more so I went back and read it and thought it was quite good.