Preheat the oven to 375 degrees F (190 degrees C).
Place red onion slices and crema in separate small bowls. Zest limes into another small bowl. Halve limes and squeeze juice into a fourth small bowl.
Stir 1 teaspoon lime juice into the bowl of crema. Add the remaining lime juice to the bowl with the red onions; stir in 1/4 teaspoon salt and let marinate at room temperature until pickled, at least 20 minutes.
Heat oil in a skillet over medium heat. Add chayote and poblano pepper; cook, stirring constantly, until golden and tender, about 10 minutes.
Coat tortillas on both sides with cooking spray. Place tortillas on a large baking sheet.
Bake in the preheated oven until crisped and lightly brown, 8 to 10 minutes.
Stir the lime zest, 1/2 the cilantro, onion powder, and 1/4 teaspoon salt into the chayote-poblano mixture. Pour mixture into a bowl.
Heat remaining 1 tablespoon oil in the same skillet over medium heat. Add ground turkey; cook, stirring occasionally, until browned, about 7 minutes. Stir in 1/4 cup water, taco seasoning, and chili powder. Cook until water has evaporated, about 4 minutes.
Spread guacamole over each crisped tortilla; top with chayote-poblano mixture, ground turkey, pickled onions, lime crema, and remaining cilantro.