If the repaired part of the egg is not in the area where the chick (duckling) will need to pip through you should be ok and should not assist. If the crack stretches over the area it will need to crack (pip) you might need to watch that area and POSSIBLY assist the duckling pipping through that part of the egg shell. As a general rule, helping embryos hatch is not a good idea, but I have had to help with more expensive chicks like Umbrella cockatoos because sometimes they just have zero chance of getting out on their own. For me and my chickens, I let nature COMPLETELY rule the roost. If the chick can't get out on its own, I consider it slightly inferior to the way nature intended and I will not want it in my breeding population anyway. Only the fittest make my breeding pens.....