Coat potatoes with 2 tsp olive oil and season generously with kosher salt and pepper.
Add 1 cup of water to the Instant Pot, then add the potatoes. Secure the Pressure Cooking Lid.
Using the display panel select the PRESSURE COOK function. Adjust the time to 22 minutes, then select START.
When the time is up, quick-release the pressure. Remove the potatoes and cool for 5 minutes.
Cut a large oval off the top of each potato and scoop out the insides into a large mixing bowl, leaving a half-inch shell, Be careful not to tear the shell.
Add butter, sour cream, milk, 1 tsp kosher salt, 1/4 tsp pepper and half the cheese to the bowl of potatoes and mix together well (a hand mixer works best for this, or you can use a potato masher or fork). Fold in the thawed and drained broccoli florets.
Generously fill the potato shells with the filling and top with remaining cheese. Use the back of a spoon to gently press the cheese into the filling.
Select CANCEL, then drain the liquid from the pot.
Place two of the potatoes in the bottom of the Air Fryer Basket. Insert the Broil Tray and place the remaining two potatoes on the Broil Tray.
Place the Air Fryer Basket on its base and lower into the pot. Secure the Air Fryer Lid.
Using the display panel select the BROIL function. Adjust the temperature to 400°F and the time to 6 minutes, then select START.
When cheese is melted and bubbly, remove the lid and place on the protective pad. Serve hot.