No options are specified.
Used by XRMeshSubsystem.GenerateMeshAsync. If the mesh provider supplies a transform and MeshGenerationOptions has this value, Unity applies the supplied transform to the vertices of the mesh, and rebakes the physics mesh. If you do not need to perform these operations, you should set MeshGenerationOptions.ConsumeTransform.
Additional resources: XRMeshSubsystem.GenerateMeshAsync, MeshGenerationResult