Only female hinnies will lay eggs, mule females will not.
Of the ones that lay, you have a 2/3% change they could be fertile (if mated with a fertile drake).
I would love to hear the results if you do!
In the research I've done, chances of fertility are really low, like 2-3%. So in the next generation you would need to set a TON of eggs in hopes that at least a few are fertile, and make it to hatching.
As for the barring, I have achieved the full...