Waffle Iron Hash Browns

Name: Waffle Iron Hash Browns
Ingredients: 1 (30-oz.) pkg. frozen shredded hash browns, thawed; 1 1/2 cups matchstick carrots (from 1 [10-oz.] pkg.); 3/4 cup thinly sliced large scallions (about 3 large); 2 Tbsp. cornstarch; 1 1/2 tsp. garlic powder; 1/2 tsp. black pepper; 1/2 cup, plus 2 Tbsp. canola or peanut oil, divided, plus more for waffle iron; 2 1/2 tsp. kosher salt, divided; 8 large eggs; 4 oz. feta cheese, crumbled (about 1 cup); 1/4 cup finely chopped fresh herbs (such as dill, chives, and mint)