No problem at all. System knows you checked in before and just Reprints the BP (sort of like you forgot to bring it with you to the airport). You will see a small r next to the number on lower left (this is the sequence that the BP are issued - so you can tell if you were # 1 or # 23 - but not much value).

So no need to really print the BP from home, especially if you are going to check bags anyway, where one can get a reissue. But if you are going straight to gate with only carryons, you will not need to stop until you hit security.

No penalty.