Place the pork ribs on a large cutting board and remove the membrane that covers the bones. To do this, slip a dull knife under the membrane, and then with the aid of a paper towel grasp membrane with fingertips, and strip it away from the bones.
Transfer ribs to a large baking sheet, pat dry, and set aside. In a small bowl, stir together the seasoned salt, pepper, 1 tsp chipotle, cumin, and sugar. Rub mixture on both sides of the ribs with your fingers.
Cover with aluminum foil and let sit for about 1 hour at room temp. Meanwhile, mix barbecue sauce, 1/2 tsp chipotle powder, garlic powder, and lime juice in a small saucepan over medium heat. Stir in and let simmer for 4-5 minutes.
Prepare charcoal grill for indirect cooking. To do this, bank charcoal into a slope against one side of the grill. Oil the grill grate. Place the ribs to cook, covered, on the part of the grate opposite the bank of coals, so that they will cook slowly over a longer amount of time.
To maximize moisture, place a small disposable aluminum pan filled with hot water on the bottom of the grill beneath the ribs. If space allows, you can set another small pan filled with hot water on the grate directly above the coals.
Position the top vent holes of the lid of the grill so that they overlie the ribs, and leave them open at least half-way. This will enhance the smoky flavor. Also open the bottom vents to about half-way initially.
After 40 minutes from the start of cooking, check ribs. If they appear to be browning/cooking too fast, cut back on the heat by narrowing down the bottom vent holes.
Keep checking every 20 minutes until ribs have cooked for about 75-85 minutes total. Brush on the sauce for the last 30 minutes of cooking. Remove when done/tender. Brush on more sauce and serve with oregano on top. Enjoy!