Finding Arrow Nodes... Then What?

Okay, so it is my understanding that the nodes of an arrow are [two] points where during the arrow's flex from launch to target follow each other in the line of flight [provided flight is tuned], and I have a basic understanding of a technique for identifying arrow nodes... But then what? What do you do with this information; why is it "important" to set up/tune? Are you trying to line up the node with the plunger, or having the plunger between the nodes; before/after?

Yeah, I'm probably not going to get a great ROI if I pursue the efforts, it's a curiosity/learning endeavor.