Oh I've taken that into account, lol. Things will happen in the story even if the players aren't there to see it, because of faction Clocks (though those will tick if the players do things in quests that would benefit any of the three factions, not through time). I think I got my bases covered with enough brush strokes that I can spin up some bullshit to bring it all back to the main story if necessary.

And yeah, I see your point. I'm doing that, though, lol. Besides the enemy mobs which I'll need for/if they decide to go a random cave or something, I'm only doing stuff I'll need in the first 5 sessions. Maps, characters, and narrative aid artwork that might/will be used afterwards will be done then. Most of the stuff already done will be reused later (unless the players decide to start killing people out of the blue), but they might see all of that stuff early on, barring one or two characters.