Preheat a 6-quart air fryer to 400°F for 3 minutes. Fork-pierce potatoes; rub with 1 teaspoon oil and 1/4 teaspoon salt. Cook 40 to 50 minutes, turning halfway, until easily pierced.

Meanwhile, cook bacon in a skillet over medium 7 to 9 minutes until crisp. Drain on paper towel; set aside.

Cool potatoes 8 minutes; halve lengthwise. Scoop out flesh, leaving 1/4-inch walls attached to skins. Reserve flesh for another use.

Brush all surfaces of 4 shells with remaining oil; add remaining salt. Cook 2 shells hollow-side down at 400°F for 5 minutes; turn hollow-side up and cook 4 minutes.

Fill each of the 2 crisp shells with one-quarter of cheddar and cooked bacon. Air fry at 375°F for 2 to 3 minutes until cheese melts. Transfer to plates; repeat crisping and filling with remaining 2 shells, cheddar, and bacon.

Plate; top each with 1 tablespoon sour cream. Serve one loaded half per side portion.