I'd like to see the Wild Card play-in be a three game series in two days with all of the games being at the higher seed's place. In that scenario, if it was 1-1 you'd play a double-header the second day to determine who moves on. Then the winning team would have to get on the plane that night and play the next day with the potential of three starters being used up. That would really penalize the Wild Card team as well as giving the division winner with the best record a huge advantage.
But I know it would never happen as the uncertainty of the double-header being necessary would not be TV-friendly.