And you know this HOW?
Because 1) I have seen some P3s change EVERY hyphen to a check-hyphen. 2) As a PP I have attempted to "fix" check-hyphens and to do so one has to try to understand what it was that the P3 was complaining about. I've emailed some and said "what were you thinking?" and they say "oops, you're right, I was basically thinking that I wished the hyphen wasn't there." Lot's of people put check-hyphen in there when they are feeling "uncomfortable." Feeling "uncomfortable" isn't *sufficient* reason to put a check-hyphen in -- because if you do so then you make the PP uncomfortable too -- and who has no recourse except a) ignore the check-hyphen. b) waste copious amounts of time trying to double check the hyphen against the author's published corpus c) write the proofer an email and hope some day they will respond honestly and tell you what they were thinking if they were thinking when they entered the check-hyphen. Many authors put hyphens in places which today make to our modern tastes feel uncomfortable. That is not enough reason to insert a check-hyphen. A check-hyphen is basically a punt to the PP -- who is no better placed to resolve the issue.