this is where you're wrong about fem's..
the only reason a plant used to make feminized seeds hermies is because of the introduction of a chemical such as collidial silver.. it's the chemical that causes the plant to stop growing female sex organs, pistils, and instead forces it to grow male sex organs, stamen.. then a breeder takes the pollen from the stamen and a, either used it on the same plant, which the resulting cross is called an s1, or selfed one, or b, used the pollen from the forced male stamen on another female plant, the result would be considered an f1 ..
i always like to use the analogy of the following.. say i worked in a factory, and one day i carelessly cut off my arm in a bad industrial accident.. ok, now i have one arm, like the guy from the fugitive if you will..
if i were to have sex with my wife, who has two arms, and i only have one, we all know that our kids will all have 2 arms each as my losing my arm wasn't genetic, it was a freak industrial accident, and unless my kids happen to have a freak industrial accident in which they lose their arms, they will go on with life with two arms, and all of their kids will have two arms as well, unless of course at any point one of them cuts off their arm in an industrial accident..
in my analogy, the industrial accident is the chemical, collidial silver, in the making of feminized seeds.. so unless at some point one were to spray their feminized plants with a chemical like c.s. to force that plant to grow male stamen, it will go on it's life being a happy feminized plant.. same with it's offspring..
now saying that, some breeders will use hermie pollen to make feminized plants, but this doesn't happen often as the resulting plants will all have that hermie trait in them, and we all know that no one will want to grow hermie prone plants, and therefore that breeders reputation will take a huge hit, and no one will be buying their fem'ed seeds..
so you can rest pretty suredly that all feminized plants are the result of the introduction of some chemical that forced that plant to grow male stamen, and therefore the seeds from said plant will be just as stable as the mother plant was before the introduction of the c.s., or in my case, till one of my kids kids decides to cut their arm off in an industrial accident..