I'm sorry to be the dike of the day
but in all honesty I don't believe something like that would be implemented into the game.
The only way I would see something like that being of value is during some sort of Defender mission (i.e. trying to hold a base)
but in any other given situation I don't think it would really work.
It's not as if your character has to pick a spot in the wastes to camp and defend it from waves of enemies.
Your most likely going to be moving around constantly rather than sitting in a spot waiting for enemies to respawn.
But remember thats just my opinion so don't let me get ya down