How to breed out stress-induced male expression?

Howdy all. Long story short I have some pretty interesting heirloom genetics that are the last of their kind, in the form of about a dozen seeds.

The problem is that they take like 11 weeks to finish indoors, and they start to push bananas out of female buds around the 5-6 week mark, so you can't just ignore them. Or weirder stuff like a stamen from a calyx, or male flowers with a mixture of pistils and stamens inside.

Is there a reliable way to eliminate this frustrating trait with such a small amount of seeds? I've done intentional breeding before and I'm familiar with the basic genetic theory, etc.

Yes you can. It will take a very long time... you'd be served well to keep them small and pick the ones that display the male or femal trait the most. Long road but good luck

Start by increasing your seed population first.

What waterproof said, pick the most female and let them self pollinate one time so you at least have seeds to work with