I once had to generate about 170K+ pdf files from latex. Took a while (~5 hours) on a desktop, so had to get a server to do it and ran pdflatex with gnu parallel. The layout was a pain, since some strings in the databases were quite long.

Then I realized that I could just have generated HTML and printed it via some headless chrome script. The rendering was more consistent, and the printing was much faster (IIRC it took about 1/3 the time.)