Each chapter is around 20-30 pages, so I think a pace of 10 pages a week (which seems to be winning in the polls) should correspond nicely to half or one third of a chapter.
I also imagine people may have different editions of the book, so I think when I set up the proper book club thread that I’ll make it clear that the weekly goal is just a suggestion. If we end up in a situation where there are just a few lines of text, I think people are more than welcome to finish it, but also not if they prefer!
My goal with starting this book club is less to ensure that people finish their book (although that is my personal goal), but to create a space where people can discuss the book, ask questions, and hopefully learn a little bit of Japanese along the way, so I don’t plan on policing anyone’s pace too closely.