Preheat your broiler.
Place 2 avocado halves in a large bowl and mash lightly with a fork.
Add mayonnaise and lemon juice, mixing until smooth and well combined.
Stir in crabmeat, 3 tablespoons cilantro, chives, serrano pepper, capers, and black pepper.
Spoon the mixture evenly into the remaining avocado halves.
Arrange filled avocados on a baking pan.
Sprinkle with shredded cheese and paprika.
Broil for 3–5 minutes until the cheese is melted and bubbly.
Remove from oven, garnish with remaining cilantro, and serve with lemon wedges.