Heat one side of the Blackstone or outdoor griddle to medium.
Place the chicken in a large bowl and season with the garlic powder, onion powder, salt, and pepper. Toss well to combine.
Melt 2 tablespoons butter on the heated side of the Blackstone.
Once the butter has melted, add the chicken and spread it out into a single layer. Cook, stirring and tossing occasionally, until cooked through, 5 to 7 minutes.
While the chicken is cooking, heat the other side of the griddle to medium heat. Working with 3 or 4 tortillas at a time, add them to the griddle to warm through, about 15 seconds per side. Transfer to a plate.
Scoop the cooked chicken into a serving bowl. Stir in the remaining 2 tablespoons butter, then add the hot sauce and mix well to evenly coat the chicken.
Serve the chicken with the tortillas, lettuce, and sour cream or dressing and let everyone assemble their own tacos.