Earlier quoted context omitted.
About that heuristic, when hiring for sysadmins in the early 2000s, I found there to be an inverse relationship between résumé quality and candidate quality (with one notable exception — résumés written in LaTeX were usually of high quality and almost always indicated a quality candidate). Originally I had a similar conception about résumés — they should be one or two pages max, should look nice, and should contain n…
How do you determine that? I wrote mine in LaTeX but submit a PDF. Usually that default LaTeX font is a dead giveaway, but I find it to be pretty ugly so I switched it out.
Or even more simply, just use your eyes. The superior line breaking algorithm is extremely obvious, with or without microtype. Then less obviously, look at ligatures, kerning etc.