Mix together the hot water, olive oil, and chicken bouillon. Add the ingredients to the Instant Pot in this order: chicken broth, chicken, spices, bbq sauce, onion, sugar, and Worcestershire sauce. Make sure to just add the bbq sauce to the top of the chicken, and not to the bottom of the insert.
Cook on manual mode for 15 minutes, then let it natural release for 10 minutes before setting it to a quick release to release the remaining pressure. Once the pressure release valve drops, you can carefully remove the lid.
Use a hand mixer to shred the chicken directly inside the pot.
If the chicken is a little more liquid than you would like, you can either pour off the excess liquid, or you can set the Instant Pot to the saute mode and mix the cornstarch and remaining 2 Tablespoons of water together. Add the cornstarch mixture to the chicken and saute to thicken it up.
Taste and add additional bbq sauce to your preference.
Heat the tortillas and then assemble the tacos with coconut coleslaw, shredded chicken, diced avocado, crumbled cojita or feta, quick pickled onions, and serve with a lime wedge.