Prepare the Chili Lime Chicken and Grilled Pineapple Salsa according to their recipes and keep warm.
Make the avocado crema: halve and pit the avocado, then add it to a blender with the sour cream, mayonnaise, 1 tablespoon lime juice, 1/2 teaspoon salt, 1/4 teaspoon ground cumin, and 1/4 teaspoon garlic powder.
Blend until smooth, scraping down the sides as needed; taste and add more lime juice or salt if desired. Refrigerate up to 4 hours if preparing ahead.
Warm the tortillas: melt the cheese on the tortillas in the microwave for a few seconds or in a skillet over medium heat until the cheese is melted.
Assemble the tacos: place the warmed, cheesy tortillas on a plate, top each with a portion of chili lime chicken, spoonfuls of grilled pineapple salsa, and a drizzle of avocado crema.