I didnt' finished, but maybe if you search "masterzhen-story" then copy id (in my file 2115)
Search this id again (if you have only single save slot there only 2 places total).
Look for "m_Value\" with number type (not bool, similar to "m_Value\": 2.0) and change number.
It may help, but there likely are other flag. Backup save before edit