Select Sauté on the Instant Potand warm 2 tablespoons of the oil. Add the chorizo and cook, stirring occasionally, until lightly browned and warmed through, about 4 minutes. Transfer the chorizo to a plate.
Warm the remaining 2 tablespoons oil in the pot. Add the onion and minced garlic and cook, stirring occasionally, until the onion is tender and translucent, about 3 minutes.
Season with salt and pepper, then add the smoked paprika, sweet paprika, granulated garlic, and saffron.
Cook, stirring often, until the onion is well coated with the spices, about 3 minutes. Pour in the wine and, using a wooden spoon, scrape up any browned bits from the pot bottom.
Add the tomatoes, rice, 4 cups of the broth, and the clams, discarding any clams that fail to close to the touch.
Lock the lid in place and turn the valve to Sealing. Press the Keep Warm/Cancel button to reset the program, then press the Manual/Pressure Cook button and set the cook time for 8 minutes at high pressure.
Turn the valve to Venting to manually release the steam. When the steam stops, carefully remove the lid, press the Keep Warm/ Cancel button to reset the program, then select Sauté.
Add the remaining 1/2 cup broth, the shrimp, and the peas and cook, stirring occasionally, until the shrimp are opaque throughout, about 5 minutes.
Divide the paella among individual bowls, discarding any clams that failed to open. Top with parsley and a squeeze of lemon juice and serve.