This is another undocumented limitation of the SALV OM: Initial Lines and Detail Screen Title is not possible in ALV (created using container) with SALV OM. These features are possible in the ALV Grid created with the CL_GUI_ALV_GRID.
In the Layout TYPE LVC_S_LAYO, we have the provision to set the Initial lines in the detail view by setting up the field DETAILINIT. We can set the title to detail screen as well by populating the value in the field DETAILTITL. These features are not available in the SALV OM. Method GET_LVC_LAYOUT of Class CL_SALV_CONTROLLER_METADATA sets the Layout to TYPE LVC_S_LAYO for the ALV GRID. In fact SALV OM only sets few fields of Layout in this method. It only populated very few fields of the LVC_S_LAYO.
Discussion in SCN forum: Detail initial lines for SALV