DefaultEngine.ini doesn't work well

Hi, there,
I have some panoramic pictures in my project, and they’re in the size of 81924096, as the docs said, I add the following content to the DefaultEngine.ini, but it didn’t work well. The Displayed size is still 40962048, and the MipGenSettings is still FromTextureGroup. So I have to change it to NoMipmaps for now in order to make the Display size 8192*4096. Is there any one konw why it doesn’t work?

[SystemSettings]
TEXTUREGROUP_World=(MinLODSize=1,MaxLODSize=8192,LODBias=0,MinMagFilter=aniso,MipFilter=point,MipGenSettings=NoMipmaps)
TEXTUREGROUP_worldNormalMap=(MinLODSize=1,MaxLODSize=8192,LODBias=0,MinMagFilter=aniso,MipFilter=point,MipGenSettings=NoMipmaps)
TEXTUREGROUP_worldSpecular=(MinLODSize=1,MaxLODSize=8192,LODBias=0,MinMagFilter=aniso,MipFilter=point,MipGenSettings=NoMipmaps)

Here’s the screenshot