Preheat air fryer to 400°. Combine flour, cornstarch, salt and baking powder. Stir in club soda just until blended (batter will be thin). Toss florets in batter; transfer to a wire rack set over a baking sheet. Let stand 5 minutes. In batches, place cauliflower on greased tray in air-fryer basket. Cook until golden brown and tender, 10-12 minutes., Meanwhile, whisk together first 6 sauce ingredients; whisk in cornstarch until smooth., In a large saucepan, heat canola oil over medium-high heat. Add chiles; cook and stir until fragrant, 1-2 minutes. Add white part of onions, garlic, ginger and orange zest; cook until fragrant, about 1 minute. Stir orange juice mixture; add to saucepan. Bring to a boil; cook and stir until thickened, 2-4 minutes., Add cauliflower to sauce; toss to coat. Serve with rice; sprinkle with thinly sliced green onions.