Book chapter or Patreon exclusive Next? (Patreon)

So I've been backed up on commissions that I owe, but I still have a long way to go on writing both of them. However it's also been a while since I worked on a book chapter and I have some patron rewards that I also owe. So what would you guys at prefer I work on next, another chapter for my book, or another Patreon exclusive one-off story?