Make the mango-avocado salsa: In a medium bowl, combine the mango, avocado, onion, cucumber, orange juice, lime juice, and cilantro and mix gently. Season to taste with salt and pepper. (Preparing the salsa in advance gives it some time to marinate and will deepen the flavor, but you can also make it while the jackfruit pressure cooks.)
Prepare the jackfruit: Drain the canned jackfruit and lightly rinse under water, shaking off excess water. Use your fingers to remove any thick cores and pull the pieces apart so that it resembles shredded pork.
Select the Sauté setting on the Instant Pot and, after a few minutes, add the oil. Once the display reads “HOT,” add the scallions and cook until browned, 1 to 2 minutes. Add the garlic, ginger, and chile pepper and cook for 1 minute, stirring frequently to prevent burning.
Add all of the Jamaican jerk seasoning, stir to coat, and cook for 30 seconds, stirring constantly, until very fragrant. Select the Cancel setting.
Add the shredded jackfruit, along with the coconut sugar, tomato paste, tamari, lime juice, and liquid smoke (if using). Stir well. Pour in 1⁄2 cup water and mix again.
Secure the lid and set the Pressure Release to Sealing. Select the Pressure Cook setting at high pressure and set the cook time to 4 minutes.
Once the 4-minute timer has completed and beeps, allow a natural pressure release. Open the pot and stir well. Transfer the jackfruit to a serving bowl.
To serve: Heat the tortillas over an open flame (I place them directly on the burner of my gas stove) and use tongs to ip them after 30 to 45 seconds or when small brown spots appear, and cook for another 15 to 30 seconds. Stack them in a clean kitchen towel or in foil to keep them warm.
Serve the jackfruit with the warmed corn tortillas, mango avocado salsa, and vegan sour cream (if using).