Attempting to make random delay particle system

Hey there,

Im trying to use the EventReceiver - Spawn and EventCreator - Spawn to create a spark effect with random delay.
This currently works for a burst like effect. However, if I want some of my emitters in the particle system to putter out(last 0.5 seconds and go from spawning 50 sparks to 0) it does not work.
I need to use this because I want all my particle emitters to play off at the same time . Rather than at random offset delays. Currently the only way I see to do this is to build a custom blueprint. This is a pretty annoying to use however, since you have to simulate to see your particle effect at work. If you are working on a huge map, simulate can take 20-40 seconds to start. Is there a better way of doing this or am I stuck with the blueprint method.

Hopefully someone can help!

Thanks for looking

can you use emitter delay? (not on the emitters since that would random each one individually but on the whole particle)
delay.jpg