I can only speak from chicken experience, but during the last 3 days in the incubator, you have to increase the humidity and stop turning the eggs. I'm sure if you put other eggs in later, this would be problematic if they weren't turned and conditions may get too wet for them.
I found some pictures of candled eggs on the internet that were really useful - but chickens of course! I'm sure they would be the same if not extremely similar for geese!
Good luck!