Creating the TOC and List of Figures for a book takes 30 mins PER generation, no mater the number of documents. Why is this so slow?? (FM 2017)
Big book? Many pages? Lots of headings?
I've found that opening all files in the book will speed up the process. With the book file active, hold down Shift as you select File > Open All Files in Book. Then create the TOC and List of FIgures.
I routinely open all the files in the book as well when doing book updates. I'm curious to see if the makes a difference for you. I haven't experienced any slow downs with book updates or making PDFs (which has been an issue in the past) in 2017.
Opening all the files significantly helped the load time.