I never got near the actual printshop (usually done abroad to cut costs), but yeah. You pick up stuff all along the production chain.
Especially when the printer offers to do some small change in the print files for "a modest added fee"... No thanks, tell me what you need and I'll fix it myself!
"All em dashes in this 200 page book have somehow been replaced with hyphens? 😨 Give me ten minutes!" 😂

Always, several times a day 🙂