The "in use" highlight for default textures of custom materials is not consistent

When there is a custom material that has had one of its default textures replaced by another texture, the default texture is not highlighted any way if the material is in use in current presentation. However, when opening another presentation in the same project, the default map is highlighted with yellow, indicating that it is referred from another project somehow.

The highlighting should be synchronized. It makes sense to always highlight the default textures at least with yellow as they are referred by the .material files.

Likely the issue is simply that the current project is not included when scanning for yellow highlight.