I'd be so happy with a 24,000 page PDF, cause then at least you know where too look, and you can the search tool. I programme Siemens hardware and the docs I need are spread out over many tens of PDFs (of 100-1500 pages). I haven't found a proper tool than can let me search and view all this documentation properly. Best I found is ripgrep with some PDF extension to search which document I need, and then use SumatraPDF for finding the right page... ughh
Use Agent Ransack (free) or better, File Locator Pro ($69) from Mythicsoft. Both include comprehensive PDF text searching. AR includes the full functionality of FLP as a 30 day trial. Money you'll recover many times over and a product you'll be using for the rest of your life. https://www.mythicsoft.com/
In the particular case of Siemens, they already did that for you.
(Migrating from S7-300 PLCs to the current S7-1500 range, I found the complete documentation package for the 1500 universe in one whopper of a pdf. Just north of 11,000 pages IIRC.)
I shared the OPs frustration when working on the S7-300, though. The docs are excellent, there's just so many of them...
