Repro steps:
* Open the scene in  the attached project
* Look at the rendering (see attached image)

From left to right the decal displays:
# Scene Depth
# World Position from Scene Depth
# HD Scene Depth
# World Position from HD Scene Depth

Expected: Result from Scene Depth node and HD Scene Depth should be the same (at LOD0 on HD Scene Depth)

Actual: Scene depth node returns an unexpected value, and makes it impossible to recompute the world position (as example use case)