Definately wait the whole 24 hours. You actually have to let the cells realign. If you incubate 'scrambled' eggs, even if the air sack is stationary, you will end up sometimes with wings and legs in the wrong places or without eyes. It's weird, but the cells actually have to realign if there was heavy movement like USPS can have.
You'll want to check the air cells if you can candle them and see well. If when you turn the egg to the side the air cell moves considerably, like to the top not just a little shift. The egg probably won't hatch.
Good luck, my first hatch I got 18 out of 30 from shipped eggs, anything over 50% is amazing. I'm sure you'll do great!