Auntie Monicas Seafood Mac and Cheese

Name: Auntie Monica's Seafood Mac and Cheese
Ingredients: 3 quarts water; 3 tablespoons plus 1/4 teaspoon kosher salt, divided; 1 pound uncooked penne or large elbow macaroni; 3 tablespoons extra-virgin olive oil, divided; 3 cups whole milk; 2 cups half-and-half; 12 ounces Gouda or Monterey Jack cheese, shredded (about 3 cups); 12 ounces Muenster or mild cheddar cheese, shredded (about 3 cups); 4 ounces Gruyère cheese, shredded (about 1 cup); 1 tablespoon unsalted butter; ¼ cup diced yellow onion; 3 tablespoons all-purpose flour; 1 tablespoon chopped fresh thyme; 2 medium garlic cloves, minced; 1 tablespoon seasoned salt (such as Lawry's); 1 tablespoon liquid shrimp-and-crab boil (such as Zatarain's) (optional); 2 to 3 teaspoon hot sauce (such as Tabasco), to taste; ½ teaspoon black pepper, divided; 1 pound peeled and deveined raw medium shrimp; 8 ounces steamed lobster (such as Luke's), chopped into chunks; 8 ounces fresh lump crabmeat, drained and picked over; Cooking spray