The notoriety around caramels wasn't about their infertility. Rather that they lay a lot of slugs and for some reason, they sometimes hatch with kinks.
Remember, we're dealing with speculation. Nobody is right or wrong. I agree with Driver. It would be unwise to keep it a secret. There's already many desert designer morphs.... Proving that females can breed would just make the price go back up, and hopefully we can see more combos...
Also... If they require some special temps to get them to breed, then that's an anomaly of its own! That would make it what you call a "wonder of the world" lol.