이중국적자 한국여권으로 출국할 수 있나요

법적으로는 미국출입국엔 미국여권, 한국출입국엔 한국여권을 사용하셔야합니다.

https://travel.state.gov/content/travel/en/legal/travel-legal-considerations/Advice-about-Possible-Loss-of-US-Nationality-Dual-Nationality/Dual-Nationality.html

U.S. nationals, including dual nationals, must use a U.S. passport to enter and leave the United States.