Pat the shrimp dry with paper towels. In a medium bowl, toss the shrimp with lime zest, smoked paprika, 1/4 teaspoon kosher salt and a pinch of black pepper until evenly coated. Let rest while you prepare the other ingredients (about 3 minutes).
Make the vinaigrette: whisk together lime juice, minced garlic, olive oil, 1/2 teaspoon salt, 1/4 teaspoon pepper, and the optional ground cumin in a small bowl. Taste and adjust salt or lime as needed. Reserve about 1 tablespoon of dressing for finishing the plated salad.
Heat a large skillet over medium-high heat and add the neutral oil. When the pan is hot and the oil shimmers, add the seasoned shrimp in a single layer. Sear 1.5–2 minutes per side until opaque and just cooked through (shrimp will curl and turn pink). Transfer to a plate and let cool for 2 minutes.
In a large bowl, toss the mixed greens, cherry tomatoes, sliced red onion and cilantro with about two-thirds of the vinaigrette so the leaves are lightly coated. Gently fold in the avocado cubes, taking care not to mash them.
Divide the dressed greens among 4 plates or bowls. Top each with a quarter of the cooked shrimp, drizzle the reserved dressing over the shrimp and avocado, and finish with a squeeze of lime and a sprinkle of flaky sea salt if using. Let the assembled salad rest for 3–5 minutes to let flavors meld before serving.