Jamaican Curry Chicken

Name: Jamaican Curry Chicken
Ingredients: 0.25 cup curry powder, divided; 2 tablespoons garlic powder; 1 tablespoon seasoned salt; 1 tablespoon onion powder; 2 teaspoons salt; 1 sprig fresh thyme, leaves stripped; 1 pinch ground allspice, or more to taste; salt and ground black pepper to taste; 2.25 pounds whole chicken, cut into pieces; 3 tablespoons vegetable oil; 3 cups water; 1 potato, diced; 0.5 cup chopped carrots; 2 scallions (green onions), chopped; 1 (1 inch) piece fresh ginger root, minced; 1 Scotch bonnet chile pepper, chopped, or to taste