In a medium bowl, combine the finely chopped small red onion, shredded carrot, and diced dill pickles. Drizzle in the lemon juice and sprinkle with half of the kosher salt, followed by the granulated sugar. Allow the quick-pickled veggies to marinate for about 10 minutes.

Bring a large pot of salted water to a rolling boil. Add the elbow macaroni and cook according to the package instructions, about 7-9 minutes, until al dente. Drain and rinse under cold water.

In a large mixing bowl, combine the drained macaroni, drained and flaked tuna, and spicy mayo. Add smoked paprika, freshly ground black pepper, and remaining kosher salt. Stir gently until evenly coated.

Carefully fold in the marinated quick-pickled veggie mixture into the pasta bowl.

Transfer the salad to a serving bowl and top with sliced scallions. Cover and refrigerate for at least 30 minutes before serving.