Set Instant Pot to sauté mode. While waiting for pot to heat, rub roast with taco seasoning.
When display reads hot, add 2 tablespoons olive oil. Place the roast in the pot and cook for 3-4 minutes on both sides to sear.
Remove roast from pot and set aside. Add the beef broth to the pot to deglaze, scraping until all brown pieces are loosened. Return the roast to the pot and cancel sauté mode.
In a small bowl combine tomatoes, remaining taco seasoning, chipotle peppers, and vinegar. Stir to combine. Pour over roast.
Secure the lid and set valve to sealing. Set to pressure cook on high for 50 minutes. At end of cook time, allow pressure to release naturally.
Remove the roast and use two forks to pull meat apart.
Set Instant Pot to sauté mode and cook, stirring occasionally, until the sauce reaches your desired consistency. Return the meat to the pot to combine OR spoon the sauce over the meat when you serve.