Combine tahini, 1 Tbsp. of the oil, lemon juice, dill, chives, sugar, ¼ tsp. salt, black pepper, and garlic powder; whisk well. Gradually whisk in water in 1 Tbsp. increments until desired consistency is achieved.
Preheat a grill or grill pan over medium-high. Lightly coat with cooking spray. Brush cut-side of romaine hearts evenly with 1 Tbsp. oil; sprinkle with remaining ¼ tsp. salt. Working in batches, place romaine hearts, cut-side down, on grill or pan. Cook until char marks appear, about 3 minutes. Use a set of tongs to transfer romaine to a plate.
Combine Frank's sauce, butter, and garlic in a bowl; whisk well. Set aside.
Heat remaining 1 Tbsp. oil in a large skillet over medium-high. Add tofu; cook 7 to 8 minutes, turning to brown all sides. Add buffalo sauce mixture, stirring constantly to fully coat tofu. Cook 2 additional minutes, until most sauce is absorbed. Remove from heat.
Place two romaine hearts on each of four plates. Divide tofu evenly over each serving. Drizzle tahini-ranch overtop. Add toppings of choice and serve.