1. Oh! It’s per material. Ok now it makes perfect sense.
2. I’ll try the different options out.
3. Kinda like camera culling, as in if it is not visible the Camera’s view, Blender doesn’t have to calculate it. But by Occlusion Culling I mean if soenthing is within the Camera’s view but not visible because something else is in the way, if you have an object in front of another object, then you cull the occluded object, meaning, Blender wouldn’t waste resources calculating the object that’s behind. A quick silly for instance I was imagining, If I have nesting dolls I could apply the holdout node to the first internal doll which is not yet visible, and basically mask out every other doll, which also isn’t visible yet.
P.S
Thanks for always answering my questions. The courses are already fantastic, but these small clarifications make ’em even better and more fun.