FWIW, @JoeCrowe’s opinion comes with hundreds if not thousands of hours of microscopic analysis and experiments… normally, I say everyone has opinions and they all stink. I’m gonna call what he has not an opinion, but at least a hypothesis if not a theory. 
1000+ posts already, and this isn’t the only thread… I’m glad you’re not arguing because he’s really not someone to do it with, on this subject. 
That said, my experience matches yours with indoor growing. I’ve gone up to 70% humidity in flower without problems, especially at higher temps it’s more about VPD than RH. Also fits with what he’s said; there’s no infected plant material in there, so it’s no big deal. 