In 6-quart pot, bring about 4 quarts of water to a boil. Cook the noodles until al dente. Drain in a colander and rinse briefly under cold water. Drain the noodles well, then pour into a bowl and toss with 2 tablespoons of the sesame oil.
In a large skillet over medium heat, cook the carrots and edamame for 2 to 3 minutes in the remaining 2 tablespoons of sesame oil. Add the scallions, garlic, and the red pepper flakes and cook, stirring, until the scallions are just softened.
Add the noodles, vinegar, sugar, and soy sauce and heat the mixture, tossing to combine it well, until the noodles are heated through. Stir in the peanuts and refrigerate until chilled, at least an hour. Remove and add chopped coriander and sesame seeds. Salt to taste. Transfer the mixture to a serving bowl and garnish with cilantro leaves. Squeeze a little lime over each serving.
Bean threads are very lightweight, so if you try compared equal weights of both, you would see that 8 ounces of bean threads gives you a lot of noodles compared to 8 ounces of thin spaghetti.