Pineapple Caberet Significance

How important is it to have read the Pineapple Caberet novella for book 8? I'm about 25% of the way through book 8 now and there have been some mentions of the Pineapple Caberet, but I read on my Kindle so I haven't read any of the extra chapters. Should I drop everything and check out the Pineapple Caberet somehow, or can I get through book 8 and then go back and check it out?