Position a rack in the center of the oven and preheat to 325 degrees F. Line a large baking sheet with parchment paper.
Put the bacon in a large saute pan and cook over medium heat until most of the fat has rendered and the bacon is crispy, about 10 minutes, stirring occasionally. Use a slotted spoon to remove the bacon to a large bowl. Increase the heat slightly (between medium and medium-high) and add the onions to the bacon fat in the pan and cook until tender, about 5 minutes, stirring occasionally. Add the garlic and cook until tender, about 1 minute, stirring constantly. Transfer to the bowl with the bacon. Stir in the chopped ribs and pulled pork. Cool completely.
Add the beef, eggs, breadcrumbs, mustard powder, smoked paprika, basil, thyme, 1 to 1 1/2 teaspoons salt (depending on how salty the ribs and pulled pork are) and several heavy grinds of pepper. Use your hands to mix until well combined. Form into a 9-by-3 1/2-inch loaf that is about 2 inches tall on the prepared baking sheet. Spread 1/4 cup of the BBQ sauce evenly over the top of the meatloaf.
Bake for 30 minutes, and then spread the remaining 1/4 cup BBQ sauce on top of the partially cooked meatloaf. Continue to bake until a thermometer inserted into the center of the meatloaf registers 160 degrees F, about 45 more minutes.