IMO, it's not likely for the double yolk egg to have one embryo absorb the second. (because the 2 embryos would be separated by the distance of the 2 yolks. But, what do I know! The situation being described: a single individual posessing genetic material from 2 distinct sets of DNA is called...
An incubator has limited capacity for eggs. Most folks who are collecting eggs to hatch have the option of picking and choosing which eggs they set. Do not set the double yolker, and there will be no embryos. Simple decision, actually: Enjoy the double yolker for breakfast, save that spot in...
May be an issue of semantics, but omphalitis is an infection. While non closure of the abdomen around the umbilicus can correct it'self in time, omphalitis is usually lethal.
Agreed. IMO, it boils down to making an ethical decision. IMO, setting an egg that has little chance of producing a...
Personally, I'd not be "setting a double just for the novelty of it". Agreed with @JaeG and @casportpony on this. Better to set eggs that have good chance of viability than to set an egg that has a very good likelihood of resulting in death for one or both embryo.