I have 4 (remaining) shipped eggs set that were due to hatch 4/22. 1/4 pipped sometime between midnight last night and 8am this morning and has since hatched successfully and is up and about in the incubator (Brinsea Mini Advanced). 2 of the eggs seem to have stopped developing and are nowhere near to mass of hatching. I still have the eggs in the incubator - "just in case" they come on, but I expect them to have expired. Final egg seems to have developed, but due to shipping, is in an egg with a 'saddle' shaped air cell. I did a quick candle and noticed some movement, but it doesn't appear that the chick has pipped internally - the air cell is quite large despite running recommended humidity throughout the hatch.
Question is - when (or if at all) I should consider assisting the chick. I haven't done anything other than the quick candle - temp and humidity recover almost immediately in the Brinsea Mini so that shouldn't be an issue. The humidity obviously spiked earlier when the one chick hatched, but has since returned to normal levels. Should I give the chick another day or two, or do I need to start making preparations to assist?