Hi, I notice that the render is half as fast and nearly twice as noisy if there are any emissive materials in the scene.
This is to be expected with most render engines, but normally there is an option to exclude emissive materials
from direct lighting and GI, and have them still appear bright. Can you add this option?
Below are two renders, both lit with several spot lights, but in the noisey one, the ceiling light material has emission turned on. with lights only = 53 seconds, with light and the emissive material = 86 seconds.