A good strain that is left late and that produces pollen will produce good FEMS. Not all strains will do this but the ones that do will put out plants that are expressed as 100% female. Will they be prone to hermi? Not any more than any other plant that is created from fem pollen. Cross them with another one though and it's a whole other story. Same for these fems too, start crossing fems with fems and you will find out real quick what happens. So if it's Not "STRESS" then why do their offspring cross out into hermies too? And trust me, if you cross your S1's with other S1's they will be hermie prone, so something happens to that plant that is more than just ethylene blocking.
If you don't wan't to run it that way it's fine but it's not a "Wrong" way to create them. If it was the "Wrong" way to produce them, then there would be a lot less really good weed in the world. There are a couple first class growers who have produced winners this way. Are they wrong, when they actually won flower of the year using this tech? And I'm also not saying it's the best way in the world to do it. But there is more than one way to skin a cat. NONE of this is new stuff, people have been creating female seeds for decades, all of this has been done before many times in many ways. We are not re-inventing the wheel.