I would keep an eye on it, but sometimes they do hatch just fine when they pip at the wrong end. It looks like it has already made decent progress for just pipping.
Interesting it almost doesn't look like yolk, but rather herniated. If it's yolk it will go down on its own, if it's herniated a vet will be your only option and even then most don't like to deal with little ducklings.
I rarely hear peeping especially when they start to unzip. It takes a lot of their energy. I don't even bother using peeps to detect life. As far as safety holes go I'm not a fan unless it's been over 48 hours. I don't think it's wise to rush nature, help when needed yes, but never rush...
Can you take a picture of the candled eggs by any chance? Here is a chart from the British Waterfowl Association for comparison of what a healthy developing duck egg should look like. Do you have a thermometer that you could lay near the eggs? If they are kept under the heat lamp they should be...