I agree that on modern hardware recompiling is pretty fast. I have a 445 page book (https://gitlab.com/jim.hefferon/toc https://gitlab.com/jim.hefferon/toc) wi

I agree that on modern hardware recompiling is pretty fast. I have a 445 page book (https://gitlab.com/jim.hefferon/toc https://gitlab.com/jim.hefferon/toc) with more than a graphic per page and lots of code inclusion, cross references, etc. The command "time pdflatex book" gives this on my 2016 laptop under Ubuntu. real 0m18.159s, user 0m17.747s, sys 0m0.296s Not instantaneous but considering the job, pretty good. I no longer bother with \includeonly.