A Niagara system will only use one spawn rate curve when it has more than one emitter with different spawn rate curves

Systems that have more than one emitter that both have unique spawn rate curves will only used the most recently added emitter's spawn rate curve for all emitters.

1. Create a Niagara emitter based on the fountain template
2. Set its spawn rate to Float from Curve
3. Edit the curve so that it has two peaks, one at the end and one at the beginning, with no particles spawning in the middle
4. Create another emitter based on the fountain
5. Change its color curve to visually distinguish it from the first one
6. Set its spawn rate to Float from Curve
7. Edit the curve so that it has one peak in the middle, with no particles spawning at the start or end.
8. Create a system with the first emitter, and observe that the particles spawn in the same pattern as the emitter
9. Add the second emitter to the system.

RESULT

When the second emitter is added the spawn curve for the second emitter is used for both emitters. The first emitter will stop spawning particles at the start and end of the loop, and will now spawn them in the middle.