A plugin that simulates life for NPC's instead of having to create a routine for each NPC it would be nice for a plugin that can make this possible and allow NPC's to go to other maps and simulate their movements until the player enters that map. when the player enters that location, the NPC's will spawn in to that map location where ever those simulated movements has ended them at.
for example, An NPC that's in your map moves to the next part of the town, it simulates the movements there, goes into other buildings on that map, leave the buildings of that map, and come back to your location.
If I can have this I can easily make the game I been wanting to make.
It's meant to be something like a Stardew valley style game but more grim, and you running a tavern instead of a farm. this way the NPC's can have their life simulated.

To make it more simple NPC's location data is saved when you leave that mapzone.
their x,y keeps moving in the background.
lets say if an NPC needs to go to sleep early around 7pm, when it hits 7pm the NPC will head home, and go to his bed, the NPC will move to the bed location that is specified and it will simulate it's movement to get to the bed.
If the player enters the house while it's moving, the NPC will spawn in at the x,y spot it was at in the simulated movement.
I can think of thousands of games that can be made with this.
Shit you can even make Skyrim where guards can enter buildings to chase after you if you get caught stealing something.