Issue
When you create a vignette in Image Authoring, you see this warning in Object Properties:
"Local Illumination Map B (C) will not be used."
Solution
The main vignette View only has one/two Illumination Maps.
Image Authoring (IA) currently considers a vignette configuration invalid when objects within the vignette reference an illumination map that doesn't exist in the main vignette.
To avoid these warnings and preserve the illumination maps, add the same amount of illumination maps to the base vignette View object. Open the View object and copy illumination map A to maps B and C (if necessary). Then, confirm that on the object page in IA, the same object no longer has any similar warnings for its local illumination map reference.