You cannot put tips in for a closed order if your Station is offline. Calling Clover support the only answer I received was to call in and they can run a 2nd transaction on the card for the tip amount. This would hit the customers card 2x and is NOT a good way to deal with this issue. If the Station is offline the tip amount should be able to be entered and stored/sent with all the other card data when the system comes back online.

If using pre-auth and the Clover is online everything works fine and the card data is stored. If for some reason the Station goes offline after a card is pre-authed (internet down, network issues, etc) you cannot use that stored/pre-authed card to close out the transaction.