I might try to do prop moves (pathfinding, idle moves, all animations, bark strinngs) for nearby neighbouring maps, too:
1. The pathfinding would only be done within the constraints of each separate map, so props will not cross these invisible lines (exception: time driven movers).
2. All mover props on current map will be caculated. Also, all props on neighbouring are calculated as long as their y-distance is 8 or less and their x distance is 13 or less to current party position. This way eg with the 32x32 default map size only 4 maps will be affected at max (corner situation: current plus 3 neighbours).