Neither the article nor any responses I see have mention the fact that Apple updated a billion live iPhones to APFS in 10.3 and there was nary a peep. Certainly

Neither the article nor any responses I see have mention the fact that Apple updated a billion live iPhones to APFS in 10.3 and there was nary a peep. Certainly that’s a testament to its stability. Anyway, the real test would have been to take an APFS drive from Ventura and test it on High Sierra and see if there are any issues. I’m guessing that APFS was written with forward compatibility in mind. If a new version writes some additional bits that the old one doesn’t know how to take advantage of, I would hope it silently ignores them without affecting any basic functionality. This article uses a lot of words to talk about writing version numbers without any thoughtful analysis on what those versus numbers might even do.