저도 STEM OPT 도중 온라인 석사 프로그램에 관심이 가서 졸업 학교 인터네셔널센터에도 문의해보고 했는데요, 아래가 답변이였습니다:
Unfortunately, I would advise against pursuing a degree (including a fully online part-time degree) while on OPT. There is not much official guidance on this but government agencies seem to be pretty strict in their interpretation of the regulations. Enrolling in part-time coursework that is not part of a degree or certificate program would be permitted.