I grew Chronic in '02 from seeds bought in person in A'dam around '99/00 and there was one pheno I had that noone would ever believe was Chronic....cuz it tasted really good and i'm a taste whore so take that for what it is. And that was back when they gave you 15 seeds per vial. But of the 15 I found a few straight up hermie-dominant plants as well as a trifoliate, which was hermie also if I remember correctly.
It's funny cuz I made a cross back then with a female Chronic that (at the time) showed zero hermie flowers and a male Yumbolt x Cafe Girl and I just recently started some of the seeds and low and behold, 2 of the 5 female Chron X YumCafe I put into bloom showed true male flowers (something i've never seen before) at the preflower sites. So it went female preflowers at nodes 5 and 6 and then node 7 started to sprout a little seperate branch/leaf and when I looked closer I swear it was an actual male bud...but it wasn't open yet so I just cut it off. Node 8 went back to normal female preflowers.
A part of me wanted to cut them down right there but I didn't because the taste is just too good and it's possible that the pollen is non-viable cuz i've seen it with other strains but those are just a few nanners towards then end of the bloom cycle...not a full on male bud
The problem w/ Chronic IMO is you probably need to get lucky or grow out a bunch of seeds to find a keeper. I've never grown CM so I can't really comment except to say it's Shanti's work so you can't really go wrong.