One of Niagara’s features is the ability to share particle data with Blueprints, enabling dynamic interactions between particle systems and other gameplay elements.
https://dev.epicgames.com/community/learning/tutorials/vaa7/unreal-engine-fortnite-export-niagara-particle-data-to-blueprint
The order of exported particles becomes messed up when going over 32 particles on GPU emitters.
This makes it impossible to synchronize particles between two different systems or really any sort of work for particles that are not identical/ should trigger different events in the blueprint.
( on gpu emitters only)