Right?! That thread is so amazing. Choosing rare breeds with often complicated hatches - especially early on when the eggs were shipped to me- that thread on assisted hatching is invaluable. It has been and is my hatching bible as it relates (not trying to be disrespectful by using the word bible. Just didn’t know how else to emphasize). I actually have it printed. The advice on that thread is the reason so many of my assists are running around happy healthy babies. The one thing I always do if a baby has been internally pipped for 24 hours is install an artificial pip hole- just a teeny tiny little hole at the top of the aircell. More often that not, I find when they don’t externally pip on their own they’re feet over head so they’re kind of wedged if you will and cannot get traction to zip. I have some excellent photos of this malposition. They always let you know when it’s time. I learned all that from that guide. I have sent countless people in an assist situation to that thread. I always say- do nothing right now. First go read the guide (that you link to) and then reread it. Then print it and read a third time. Then and only then, help - but proceed with caution. One thing that always sticks in my mind from that- to paraphrase is- help and put the egg back. And help and put back. Repeat. And that the egg has kept them safe and alive for 21 days this far. They don’t need out this second. Such. Good. Advice. I love this site.I helped too soon.
The chick or duckling died.
It could not be fixed.
Learned when assisting, chicks & ducklings that are malpositioned like these two, that they need an extra day or two before helping more.
For info on assisting, check out this article by @Pyxis:
Guide to Assisted Hatching for All Poultry