Brine: In a medium bowl, whisk buttermilk, hot sauce, and salt. Add chicken cubes and toss to coat. Cover and refrigerate 30 minutes (up to 4 hours).
Set up dredge station: In bowl 1, whisk flour and cornstarch. In bowl 2, beat eggs. In bowl 3, mix panko, smoked paprika, garlic powder, onion powder, and pepper.
Preheat: Run air fryer empty at 400°F (200°C) for 3 minutes.
Bread: Lift chicken from buttermilk, letting excess drip off. Dredge in flour mixture, then egg, then press firmly into seasoned panko. Place on a tray.
First batch: Spray air fryer basket with oil. Arrange chicken in a single layer with space between pieces. Spritz tops with oil. Air fry at 400°F for 8–10 minutes, flipping and re-spraying at the 5-minute mark, until deeply golden and 165°F internal.
Rest and serve: Transfer to a wire rack (not paper towels). Repeat with remaining batches. Serve immediately with dipping sauces.