Dense LaTeX cheat sheets: re-render and check page count after every small addition

When adding content to a tiny-font, multi-column LaTeX sheet (multicols* with a custom 6.8 pt normalsize), compile and check the page count with pdfinfo after each batch of edits, then render with pdftoppm and look at the result. multicols* does not warn clearly when content spills onto an extra page, and a raw text check will not reveal cramped or broken lines. For scripted text edits, assert that each target string occurs exactly once before replacing it, so a repeated formula is not changed in the wrong place.