The `DeltaProjectionFunc` introduced in cbe2bb6755 was always using a
"worldspace" plane [which ignored the layer rotations for projections --
be it through actual layer transforms or object rotations].
So to resolve, use the appropriate axis of the (already available)
`layer_to_world` matrix.
Pull Request: https://projects.blender.org/blender/blender/pulls/132690
348332783f