Hard-boil the eggs. Place eggs in a pot, cover with cold water by an inch, and bring to a gentle boil. Turn off heat, cover, and let sit for 10–12 minutes.
Transfer to an ice bath for 10 minutes, then peel.
Halve and scoop. Slice eggs lengthwise. Gently pop out the yolks into a mixing bowl and set the whites on a platter.
Make the filling. Mash yolks with mayo, Greek yogurt, and lime juice until smooth. Stir in Dijon, pickled jalapeños, red onion, chili powder, cumin, garlic powder, salt, and pepper.
If using avocado, mash it well and fold it in. Adjust lime and salt to taste.
Adjust texture. If the mixture seems thick, add a teaspoon of yogurt or a touch more lime juice. You want it creamy and pipeable, not runny.
Fill the egg whites. Spoon or pipe the filling into the egg whites, mounding it slightly.
Garnish. Sprinkle with smoked paprika or Tajín.
Top with cilantro, a few crumbles of cotija, and a thin slice of jalapeño if you like extra heat.
Chill briefly. Refrigerate for 20–30 minutes to set the flavors. Serve with lime wedges on the side.