From the rules: "Players should keep their game's final save file. Although file submission is not standard for Epics games, the game's Sponsor or an Epics organizer may request files from players for verification purposes. In addition to the final saves, players may want to keep save files from earlier points in the game to enhance discussion. Sponsors may choose to require saves at particular points in the game, although this is not standard for every event. If earlier saves are necessary, this information will be provided when the game is announced."
Translation- Most of the time, all you need to do is keep a copy of your final save file, but don't submit it unless you're asked to. I think we've had a "pop quiz" file submission for one Epic in the past, and we certainly reserve the right to ask for them in the future if that seems to be indicated.
I also personally find it interesting to be able to check my own saves during the discussion to compare my game to others'. YMMV as far as that goes, especially if your notes make more sense than mine usually do.