It's a possibility that we'll see more of the codec again as I am a believer in absolute continuity. This means everything done at some point in the series actually happened, always happened, and is always able to be touched upon again later on. This means there are certain jokes I can't do because they have story consequences (i.e. I can't kill everyone ATHF style at the end of an episode with an atomic bomb just for WTF humor as that would invariably be the end of the series as I can't have them all be okay the next episode as if it didn't happen), on the other hand it means we can have jokes that reward long time watchers with a memory as well.
It's unlikely that FATE will hack into Crono's codec though, for one reason. FATE is created with the aid of Balthasar at a point after the Day of Lavos, and is then thrown into the past. Thus until the Day of Lavos is stopped, FATE doesn't exist. On the other hand I do intend to show how the changes to the past change Porre over time. Culminating in actual showing of the Porre Invasion (assuming we ever get that far) after the end of the story, so it might be possible there as FATE would then exist but I wonder if I'd even still remember the suggestion by then.