all fdd is trying to explain is that even if you have a hermie that has VERY weak hermie traits, and under fairly stable conditions wont show those hermie traits, but under the extreme stress you are talking about, burnt lights, light schedule fluctuations, ect, will hermie, it is still a hermie..
whether or not it stays 100% female for 97% of the grow, but hermies on its own from stress or by itself, it is a hermie...
a true female will ONLY produce pollen sacs through chemical induction... no amount of environmental stress will or can make a "true female" produce pollen..
you are probably right with the idea that some breeder threw a hermie in with some females and realized you can eliminate "pure males" this way... and that the stronger the female trait, the less likely the seeds were to produce hermies, although you would still get a few hermie seeds and the hermie trait was carried down... but that ultimately if you took a "true female" and chemical induced pollen sacs, with G.A or C.S.. the pollen contained would only produce "true females" because the hermie trait was/is non existent in them.... thus producing truely femenized seeds...
and your right... G.A is harmful.. but C.S isnt at all... i would assume that C.S is more of a standard now...
and lastly.. in nature, if there is a patch of females around one another, with no males present, it is possible for one or more of those females to actually produce pollen and release it as a means to ensure survival... this is mother nature's handy work... just the need to survive.. although, with true females, i think evolution of the plant would need to occur.. left alone, except to pollinate with more true female pollen until the plant adapted and "evolved", i would think true females would start doing this.. could very well be wrong tho...