I also found that having a file extension on the ini setting seemed to break the loading.
You would want it to be:
TexturePath=/Game/Textures/loadingScreen_gearvr
No .loadingScreen_gearvr, no .uasset.
To be clear: i had to both remove the file extension, and make sure the asset was cooked.
Making this a UProperty should fix both of these pitfalls.