In Instant Pot, combine coconut milk, peanut butter, soy sauce, green beans, shallot, and remaining 2 tablespoons curry paste. Place chicken in pot on top of vegetables.
Cover and set release valve to the venting position. Select Slow Cook and cook on low for 5 hours, or until chicken is cooked through (165°F).
Transfer chicken to cutting board. Skim and discard fat from cooking liquid. Stir remaining 1/4 teaspoon salt into cooking liquid. Pull meat from bones (discard fat, bones, and gristle); return to pot. Toss with cooked rice noodles.
Serve with chopped peanuts, cilantro, and lime wedges.