Instant Pot Pulled Pork

Combine the brown sugar, garlic powder, onion powder, smoked paprika, salt, pepper, mustard, and cumin to make the spice rub. Coat the meat with the rub on all sides.
Heat the oil in the instant pot on sauté mode. Add a few pieces of meat at a time, searing on all sides, making sure not to overcrowd the pot. Continue until all the meat has been browned, adding a little extra oil as you go, if needed. If you add too much meat at once, it will steam instead of getting a good sear.
Add a splash of the water or chicken broth and scrape up any crispy bits stuck to the bottom of the instant pot with a wooden spoon or spatula. Then add the rest of the water/chicken broth, 1 cup of bbq sauce, apple cider vinegar, and liquid smoke (if using). Stir to combine and then add back in all the seared meat.
Place the lid on the pot and set the seal. Cook on high pressure for 60 minutes. Let the pressure naturally release on its own for 20 minutes, then manually release any remaining pressure.
Drain some or most of the remaining liquid (depending on how juicy you like it) after the meat has cooked. Then use two forks and shred the meat, removing any large fat pieces that didn't dissolve. Add the remaining 1 cup of BBQ sauce and toss to combine, then serve as desired.