Niagara Particle Limit?

Hi all,
just curious if anyone has any experience with memory load and particle limit optimization.

let’s assume this.
I have a variable particle system that spawns in things which can either live forever or die instantly based on game code.

I’m curious as to how to optimize or eliminate those particles that can live forever when the memory limit is reached / does the engine already garbage collect for us when niagara is ordered to spawn more particles?
how can we control the memory treshold for these GPU sprites?