Trim the excess fat from the ribs.
Turn the saute feature on to heat the pressure cooker. Season the meat with salt, pepper, and onion powder.
Add 1 tablespoon olive oil to the pressure cooker and sear the meat on all sides until brown. You may need to do this in batches so the meat sears. Turn off the saute function and add all the pork back to the pot.
Meanwhile, in a small bowl, whisk together the rice wine vinegar, soy sauce, grated ginger, minced garlic, green onions, chili-garlic sauce, and brown sugar. Pour this sauce over the pork in the pressure cooker.
Close the lid and set the pressure cooker to Manual mode for 45 minutes. Allow for natural release for 15 minutes and you'll have tender, shreddable pork in under an hour.
Shred the pork. and remove it from the Instant Pot, leaving the liquid behind.
Remove 1/4 cup of the liquid to a small bowl. Add 1 tablespoon corn starch and stir to combine.
Turn on the saute function on the pressure cooker. Add the corn starch slurry to the pot and bring the mixture to a boil. Add 2 tablespoons of brown sugar and stir until combined. Cook for 1-2 minutes until the sauce thickens. This can burn, so don't walk away. Remove the pot liner from the pressure cooker. At this point, you can either add the pork back to the pot to mix with the sweet sauce, or you can use it as a drizzling sauce over the tacos.