My suggestions here:
If you use Standard-Particles, bake them when ever you can, it makes it easier to check the scene
Do not place a Sketch ‘n’ Toons to many objects (hierarchy -again and again) if they don’t change… What makes no change might only harm a scene (e.g., slows down), just a rule of thumb.
You have more option with “particles” if the Particle Emitter is used in the MoGraph Cloner as “Object”
If the MoGraph Cloner is used, this should have the Sketch ‘n’ Toons Texture Tag.
If you like “Outline” an effect, then this would be the one to choose in the SnT tag first. It wasn’t in use at all. With the Cloner, perhaps some other parts need to be enabled as well
I’m not certain how well SnT is working with “Render Instances”, I would avoid it (perhaps the support has a better idea it!)
I have set the Stroke-color to something identifiable—just for the test.
Please note that I unchecked AA for the test, set the HyperNURBS (Subdivision Surface in R15) to 1/1, and the render output to 1/4, current frame. Just to make some progress. Any context not needed for the “particle/clone objects” is off as well.
Good Luck.
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