Nice I was just about to ask for this very feature when I saw this discussion... even better if there was a absolute cold zone that doesn't even have a cost it just never get considered in the neightbours of tiles.
So whenever A* does its magical
foreach (node n in neighbours):
if (absoluteColdZone)continue;

Very dangerous feature for many also I wonder if setting the cost to an high number may cause the gains to be lost to the last few tiles of a pawn pathfinding. Say a pawn wants to go from his bed to the kitchen and take a meal... you set a very good path with the Avoid zone from his bed to the kitchen but not the meals so the meals themselves are 2 squares into the avoid zone.

Does the Avoid zone apply to enemies and allies or only to player owned pawns? I've been having issues with pawns pathing through a mech cluster, so this feature is great to stop that. I'm just curious if it will affect the enemies too by accident