Outside of the Democratic Progressive Party, Yiong has supported a number of causes as an activist. He was a member of the Culture and History Council at the Community Construction Society and the Alliance to Preserve Four Four South Village as a National Relic. Both organizations supported the preservation of Four Four South Village as a historic site. Yiong's continued activism led to him becoming a founding member of Taiwan Friends of Tibet, and Taiwan Friends of Uyghurs. Yiong has served as the deputy chairman of Taiwan Friends of Tibet, and the executive director of the Deng Liberty Foundation. While affiliated with Taiwan Friends of Tibet, Yiong called for the government to grant asylum to Tibetans in Taiwan, distributed flyers at the Taipei Zoo, participated in several commemorations of the 1959 Tibetan uprising, and petitioned the Ma Ying-jeou presidential administration regarding human rights in Tibet.