Here is a simple setup: PS has PS(1) as sub emitter.
PS emits particles upwards, PS(1) emits particles to the right. So we can see a 2d grid of particles, because each particle of PS emits particles of PS(1):
Hey, I’m using the last version (5.3.5f1), and it doesn’t seem to work on my side.
The project attached. (Just the project in a zip, is it what you needed?)
So, there’s particle system in the scene, which has a sub emitter, which has a curve controlling emission. And the curve works exactly as the constant do. It seems like even if sub emitter has a curve, only the first (most left) value is used for its emission. So even if we add more keys, they don’t affect emission rate. But this issue doesn’t exist if the emitter is independent.