Place the tortillas in the oven in two stacks; heat to 200°. In a bowl, mash the avocados with the lemon juice; season with salt and pepper.
Working in batches, in a nonstick skillet, cook the bacon over medium heat until crisp; drain on paper towels. Leave about 2 tablespoons bacon fat in the skillet, reserving the rest of the fat. Cut the bacon strips in half.
Working in 2 batches, in the skillet, cook the eggs over easy; transfer to a platter. Reserve the skillet.
Lay the tortillas on a work surface. Sprinkle each with 1/4 cup cheese; top with beans, 1 egg and bacon strips, then fold to enclose.
In the same skillet, heat 1 tablespoon reserved bacon fat over medium heat, add 4 quesadillas and cook, turning once, until crisp and golden, about 3 minutes.
Repeat with more bacon fat and the remaining quesadillas; serve with the avocado mash.