They both suck. But one is for sure getting the job. Which one do you want? You have to pick one. You can protest it and hope to change it, but nothing like that can happen in time, you will be stuck with one of these two people. Please at least try to pick the one that has less terrible things on their resume and then actually protest for proper change. If you pick the wrong guy, you also won’t be able to protest for any kind of change.
Well, you got the answers you were looking for, here is a different answer. To your other implied question, how to not worry about dust getting in other holes.
Main thing is to develop positive air pressure. You want more powered intake than powered exhaust.
Use fans for all your filtered air intakes, ignore powered air exhaust, run it at lower fan speeds if you can. Air will get out fine. If you force the air in where you want it to go in, dust will only go into the easily removable filters, it won’t be on your components. Any extra hole in the case will just be exhausting the already filtered air. Then just remember to actually check and clean your filters. That’s the hard part. But if you clean them when they need to be cleaned, you will never have to actually clean the inside or the fans or components or anything else, just the filters.