hmm, i thought its a bit different. you still get males and females in normal proportions, but the males are very likely to get the banana gene, and the females will be very unlikely to get the banana gene.
so you get mostly male bananas and normal females, with the occasional exception of a male normal or a female banana every now and then.
when the follicles are formed, even before they are fertilized, the gender is already set in stone.
anyway, very nice addition, i love the optics of the banana morph, i wish you good luck with spreading the gene around in your collection and getting it into recessive combos.