Promotes the release of ascospores from asci by hydrolyzing 1,3-alpha-glucan in the ascus wall. Endohydrolysis of (1->3)-alpha-D-glucosidic linkages in isolichenin, pseudonigeran and nigeran. Present during vegetative growth at low level (at protein level) (PubMed:19542306). The level increases throughout meiosis and reaches its highest during sporulation (at protein level) (PubMed:19542306). Abolishes ascospore release from ascus during sporulation. Belongs to the glycosyl hydrolase 71 family.