If you are one of the unfortunate homeowner’s to have a specific type of concrete roof tile made by Monier, I feel sorry for you. The Monier Homestead concrete roof tile has been discontinued by the manufacturer for some time now. Perhaps a decade? Now why would a manufacturer do something like that?… and especially to home owners who are supposed to be their valued clients! The reason is that a systemic failure occurs due to a design flaw.
I believe the slight curvature of the tile causes breakage to the top left hand corner of the tiles. Foot traffic on the roof adds to the probability of breakage. But you need to walk on your roof to uphold maintenance requirements you say. I agree. Leaks happen too and not just because of the systemic design flaw. Those leaks need to be addressed.
Now here’s the biggest kicker of all though. You can’t see those cracked corners because the tile placed above and also the tile placed beside the one OR MANY that cracked is concealing it. Try and find a needle in a haystack. You’ll have more luck.