Preheat oven to 400°F. Arrange 8 slices bacon in a single layer on a wire rack set inside a foil-lined rimmed baking sheet. Bake until browned and crisp, 18–25 minutes. Transfer to paper towels to drain.
Whisk 10 large eggs in a medium bowl until smooth. Melt 4 Tbsp. unsalted butter in a large nonstick skillet over medium. Pour eggs into pan and immediately start pushing them across the bottom with a heatproof rubber spatula. Cook, scraping bottom and sides, until large curds form but mixture is still a little runny, about 2 minutes. Scatter 1 cup coarsely grated Oaxaca or Chihuahua cheese over and cook, folding into eggs, until cheese is melted and eggs are cooked through, 1–2 minutes. Remove from heat.
Arrange 4 Homemade Flour Tortillas, warmed, on a surface and divide ¾ cup Creamy Black Beans, warmed, among tortillas, spreading down center of each. Top with eggs and 2 cups crushed tostadas or tortilla chips, dividing evenly, followed by bacon and more cheese (if desired). Fold one side of tortilla up and over filling, then roll up to enclose. If not eating immediately, wrap in foil to keep warm. Store at room temperature up to 1 hour. Do ahead: Burritos can be made 6 hours ahead; chill. Unwrap and reheat in a cast-iron skillet over medium-low to medium 1–2 minutes on each side.
