Mix together the salt, garlic and thyme and rub on both sides of the rack of ribs until well seasoned. pan>
Slice the rack of ribs into three equal-sized portions and lay them in the bottom of the Instant Pot. Pour the liquid around (not on top) of the ribs. Set the Instant Pot to cook on the "Manual" setting for 50 minutes. Let pressure release naturally when timer goes off.
Whisk together the maple and tamarind until combined and heat your oven broiler to 425 degrees. Arrange the top oven rack 6 to 8 inches away from the broiler element.
Place the cooked ribs on a rimmed baking sheet meaty side up and baste with half of the maple-tamarind sauce. Broil for 5 to 7 minutes until bubbling and caramelized, remove from oven, and baste with additional maple-tamarind sauce. Broil for another 3 to 5 minutes until caramelized. Season with additional sea salt and serve immediately.