In then end, of the 8 I locked down, 7 hatched. Of those, 6 are male, and 1 is female. (The reason for my second hatching is the outcome of the first: 3 males and 1 female. These are not the ratios I was hoping for! Is it typical for more male ducklings to hatch from shipped eggs? I am really wondering if somehow the females are more fragile and susceptible to the abuse the postal service dishes out?) I would really like to know the answer to this question!
I say 6 males hatched, but my last little boy didn't make it to a complete hatch.

His first pip barely made a divot in the eggshell, and when I checked up on it hours later, I discovered that he had not punctured the membrane. I made him an emergency air hole, which he enlarged slightly, but he did not progress past that point. I opened the shell some more to make sure he could breathe, but stopped when there was bleeding and let him sit. I checked numerous times, coated the intact parts of the membrane with coconut oil, and kept waiting because it looked like he wasn't done absorbing the blood. Sometime in the early hours of the morning he died.

I was heartbroken to find him that way. When I peeled away the shell, I discovered that he still had a large portion of unabsorbed yolk ballooned out from him. Not normal, of course, for the amount of hours it took. I suppose that if I had removed the shell earlier and found that, and he had died, I would have blamed his death on intervention that was premature.
Perhaps more quickly breaking him out of the shell might have saved him, but there is no way of knowing. He looked perfect in every way except for the yolk. I can say that if this sort of scenario happens again, I will be more quick to fully assist. There are risks both ways, but it is possible that a more cautious approach did harm in this case. Again, it's impossible to know for sure.
He does have five bouncing brothers and one sister growing in the brooder now. I am not sure what I am going to do about the unbalanced ratio, as I now have 8 drakes and 2 hens from the last two hatches combined! Dear heavens, if it had only been reversed. Guess I'll have to figure that out in the next couple of months, but I am NOT keen on hatching shipped duck eggs again. Just too hard on them.