The problem with candling too often is that every time you open the incubator, you lose humidity and every time you handle the eggs you risk introducing bacteria into the incubator.
You may be able to candle them without picking them up, but that entails keeping the incubator open, so it is a trade off.
There are also some questions about whether keeping a very strong light on a developing embryo for extended time could damage their vision.
I dont know if that is true.
Anyway, I would recommend avoiding excessive candling even though it is really fun.
Just put down the flashlight and back away from the incubator.