Luohou transmitted the location of Penglai Island to Taishang. Today, Penglai Island has become an island beneath Heavenly Dao, and its location is now fixed!
Therefore, Taishang could find it simply by knowing the coordinates.
It was just that Luohou did not know whether Taixuan had gone to Penglai Island, though in Luohou's view, he likely had, given that Luohou originally intended to bestow Penglai Island upon Taixuan.
Chapter 144