I believe you can think about intervening when it has been 24 hours, as long as they can breath, they are usually fine. My last hatch I had to assist 3 Marans that pipped a very small hole but made no progress after 26 hours. There are some threads here you can look up how to do it so you are ready if you need to help. All 3 that I helped are fine now at 2 weeks of age. I set up a heat lamp, hot water and towels to keep the humidity up while I gently used tweezers on the egg.We have a little more progress. Right was at 7 am. Left was around 1pm. It's 7pm now. When should there be now progress before I should start to worry? We lost one it does start internally pipping. It internally pipped last night. And was dead this morning.
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