Very VERY quick summary.
Yesterday I found an abandoned nest. It was confirmed abandoned and 2 eggs were dead, one duckling hatched, and 2 still alive. Duckling was adopted by someone else and I took care of the eggs. Something I've noticed is that they both seem to have issues actually breaking the outer membrane adjacent to the shell. They will both peck at it and cause quite a swatch of broken shell, but I had to put a hole in both. And the first one to hatch had a heck of a time and needed a gentle guiding hand out.
Is this a malposition of some kind? The first one began to turn but obstructed its own air supply. And seemed to be having some kind of difficulty even breaking the outer membrane. I went ahead and opened up a hole for the other one to breath and it's still absorbing. But this is 2 in a row that have this issue. I suspect the abandoned nest being left out in the sun for a full day before I stepped in to help might have affected the egg conditions a bit. But I could really use a second opinion in understanding this anomalous condition. I've hatched dozens of ducks in the last few years and these are the first two that seriously needed help aside from a batch of call ducks a few years ago.