Emitter lifetime at start

[AggrorJorn]

Josh, would you kindly add a 'LifeTime at start' variable for emitters? Unless there already is a creative way to do this.

I am creating a very simple swamp cloud emitter. They cover a rather large area and thus take some time before they cover the area I would like them to cover. 

Since the player can load the game while looking at the emitter area, the player sees these emitters in their 'start-up' time.

I can gimmick around this (multiple smaller emitter, waiting a couple of seconds before showing the game etc), but I would like to see a more professional option for this.