Yes I have another incubator luckily lol it's her first eggs so not sure if fertile yet or not crossing fingers no harm in trying
Eggs should be candled pre set . Since geese ducks and other water fowl take longer to incubate than chickens and such . Noticeable development will be slower showing. Eggs will become cloudy before veins appear . With that in mind the preset candle gives you a starting point . Early candling or dark egg candling you look for the clouding . In some darker eggs you can't ever see the veins .Clouding first and a gradual progression to veins and total darkness . Pictures taken at preset candles are great for first time hatchers . They give them something to compare to at each candling . I have college text books that say you can candle as often as you like . As long as you don't let the temperature of the egg drop drastically . Eggs getting to hot will hurt them far more than cooling off a little . You already had the answer to your question without even realizing it . Knowledge in hatching is gained with experience . No one with a thousand eggs in incubation is going to candle them all . But no one in their right mind would load that many eggs without making sure they weren't cracked or pin holed first . That is only asking for trouble . Good luck with your set 
Hope we here of a gaggle of geese from you soon .
