In a large cast iron skillet over high, heat 1 tablespoon of the oil. Add fresh or frozen corn and white and light green parts of the green onion, and season with salt and pepper. Cook, tossing halfway through, until charred in places, about 4 minutes.
Transfer corn into a large bowl and wipe the skillet. Let corn cool slightly and toss with cilantro, cotija cheese, dark parts of the green onion, 2 tablespoons of the lime juice, and jalapeño.
Meanwhile, return skillet to medium heat. Add remaining tablespoon oil and frozen chicken. Cook, stirring occasionally, until chicken is warm, about 5 minutes. Remove from heat.
In a small bowl, make your taco topping: Whisk mayonnaise, sour cream, the remaining 2 teaspoons of lime juice, chili powder, and paprika until well combined. Season with salt and pepper and set aside.
Using tongs, hold each tortilla directly over a gas flame, turning, until heated through, about 5 seconds.
Serve tortillas stuffed with chicken, avocado, and the corn mixture. Dollop with mayonnaise mixture and sprinkle with more cotija cheese. Serve warm with lime wedges.