I know you feel guilty and like you "should do something". However shipping hatching is a risk, and we all assume the risk when we swap as well. The fact that you replaced a non-paid for set of eggs says a lot. You dont owe anything else at this point, you full fileld the swap with the first box you shipped, and were kind enough to reship because of broken eggs thanks to the USPS. if someone is swapping and expecting all shipments to be replaced if any are broke, or if the USPS looses and or delays a box they need to STOP swapping.I just called the PO and they told me the eggs to brkuk where delivered. Hm.
I shipped them on the 6th, that's a long time for eggs to be sitting before development.
I got eggs from this swap and not a one was usable thanks to breaks, cracks and egg goo everywhere. Just the luck of the draw for me and those swaps.