A similar discussion took place recently in this forum thread, so that may be of some interest.
But to answer the wider question of carrying (non-achievement) game information from one playthrough to the next, the only certain way is to devise your own save system using something like Javascript and a database, and ChoiceScript’s *script command. Its only practical purpose would be for beta testing though (i.e. it probably wouldn’t survive the publication process via CoG) so is probably not worth implementing for just the purpose you mention there.