Heat the oven to 400 degrees. Lay the bacon in an even layer on a rimmed baking sheet and bake until browned and crisp, 15 to 20 minutes. Transfer to a paper towel-line plate and let cool.
While bacon is coking, in a medium bowl, toss together tomatoes, jalapeno, cilantro, lime juice and a large pinch of salt. Taste and add more lime juice and salt, if needed.
In a small bowl, whisk together the mayonnaise and hot sauce.
Warm the tortillas using an open gas flame or a dry skillet over medium heat, about 30 seconds to 1 minute per side, until soft and lightly charred. As you go, stack them in a clean kitchen towel-lined bowl or a tortilla warmer to keep them warm. Cover tightly. You can also make homemade tortillas in advance—just reheat before serving.
Serve, letting each person make their own tacos by layering bacon, salsa, lettuce, spicy mayonnaise and avocado (if using) on tortillas. Top with more hot sauce if desired.