You are probably fine, just make sure you keep the membranes moist and the humidity high to reduce the chances of shrink wrapping (inner membrane drying up and shrinking on the chick). Keep an eye on it.
Good to know! I was trying to get the duck folks to look at your issue. I'm confident talking about assisting chicks, but ducks are a different beast (pun intended) and have their own idiosyncrasies. I've never hatched ducks so I don't know the rules about helping them.
I generally don't help chicks unless they pip on their own. I've never had it turn out well (with chicken eggs anyway). If your chicks are DIS (dead in shell) at that late stage, that usually means you are having temperature issues.
If you are so inclined, you can start peeling back the shell...
I would leave any eggs that haven’t pipped externally alone. I’ve never had a good outcome helping a chick that didn’t pip on its own. With the chick that has pipped on its own, you can try peeling the egg and membrane back towards the air cell as long as there is no bleeding. There is an inner...
If you want you can put in a safety hole. My rule of thumb, if they can't pip externally, they most likely can't survive outside the egg. No chick that I've helped pip came to a good end.
I love my brinsea incubators! I both the 28 EX two years ago. I just bought the 56 eco last week because my frankenbators aren't steady enough for starting eggs and I was getting bad hatch rates with eggs started in my frankenbators.
Did it pip in the circle? If so, that isn't really a wrong end pip, just a below the air cell pip. I think that the two shadows you are probably seeing are a beak and wing, not twins.
Sounds like you are doing your best. I find wrong end pippers the hardest to help if they can't hatch mostly on their own. They usually have some sort of developmental issue that prevents them from turning in the proper direction and being strong enough to hatch on their own. If you think it is...