If you are still drawing from American history as an influence, I suggest that writing an arc based on the Civil War might prove interesting. Considering first and foremost that this is fantasy, you could force players to face the question of slavery directly and dynamically; in RPPR's actual play, although the topic has been addressed lightly in the past, it has always been the business of private enterprises and the colony as a whole does not seem to have an official standing (unless I missed something, i.e.).
The supplement could very well play into separating the party into sides as a specific mechanic. Whatever the case, you have the ethical argument and politics as RP fodder and, on the other hand, the war itself as the stage for encounters.
Just a thought, anyway.