Okay, so when you have multiple emitters, you'd like to control exactly when each one starts when everything is rendered/played ?
Actually, the Delay option is enough to set each emitter starting time. But it doesn't work when looping is enabled.
My main concern is looping. What I expect about the looping is only to show me the animation repeatedly with the delay at the start and the fading of particles (if any) at then end. When I enable looping, I only see a permanent emission of particles seamlessly. This is not accurate with the settings I set. I don't know how to explain better than this. Sorry.
I understand what you mean now. I've had a quick look into it, but it turns out it's not as straight forward as I hoped, so I'll need more time to think of a good way to implement it without breaking anything else