Chop pork roast into 4 to 6 large chunks. Sprinkle the chunks of pork liberally with sea salt, followed by the paprika, oregano, onion powder, and garlic powder.
Plug in your Instant Pot (or pressure cooker) and turn it to the Saute function. Add the oil and onion. Saute, stirring occasionally, until onion is translucent. Push onion off to the side to make room to brown the meat.
Place the chunks of meat on the hot surface of the Instant Pot and brown on two sides for 3 to 4 minutes each. Pour in the broth and lime juice (and lime rinds if desired). Secure the lid and turn Instant Pot on to the high Pressure Cook setting, setting the time for 40 minutes and leaving the steam release valve on Sealing. Allow Instant Pot to go into the Keep Warm mode for at least 30 minutes. Use the quick release to release any remaining pressure.
Open the lid and use tongs to transfer meat to a cutting board. Use two forks to shred the meat. Place the shredded pork back into the Instant Pot to allow it to soak up the juices for at least 15 minutes (note: you can store the shredded pork in the juice to make it even more flavorful until you’re ready to eat it).
When ready to eat, place oven on the high broil setting and transfer shredded carnitas to a large baking sheet Place baking sheet on the rack that’s second to the top and allow it to broil for 3 to 5 minutes, until it reaches the desired level of crisp.
Serve carnitas taco-style, as a burrito bowl, and/or with side dishes of choice.