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Most likely they'll be fine, there's a very small percentage of feminized seeds that go hermie - if you look through my Test thread you'd see that for every strain someone says hermied several other people come on and say that they've run that fem strain for years and never a problem. And Barney's Farm is a top shelf breeder.
If it does hermie there's only 3 options I've found (other than letting the bananas mature): chop it; pick each banana with tweezers (could be an hour per large plant each day, can be horrible.); spray with Penetrator and Reverse. Best to have a liter of each on hand before the problem starts.
BUT, most likely you'll have no problem.
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