If one egg is pipped, I usually feel comfortable cutting the eggs. Others think you shouldn't ever do it. I think(My opinion, not based on any scientific studies!!!) that some eggs absorb more humidity than others in the clutch, so some are more dimpled, and some are more "plump".
If the snake is moving around good, you could wait a while. I don't think there's anything wrong with it.
AGAIN... only my opinion based on the FEW clutches I've hatched.