You'll want to do it in sequence: 1,2,3. New data fields will be added each time, so 3 won't be able to correctly read a file from 1. This isn't really a loss though, as the whole point of these side scenes is that they gradually develop as you play the games. So if you care about them, you're probably buying and playing all the games anyway. To be clear, I'm talking about the EXTRA save system, the DataCrystal files. Normal saves have never transferred, and never will.