• Create 3D project
• Add Glass material to project from Content Library/Materials
• Set Glass to the cubeModel
• Add cubeModel to content library
• Create another 3D project
• Add instance of cubeModel to the scene
• Check content of <project folder>/Generated/Bundles/User3D

--> There is GlassMaterial.qml and MyCubeMaterial.qml. qmldir file also has both.

• Remove cubeModel from project via content library context menu
• Check content of <project folder>/Generated/Bundles/User3D

--> .qml files have been removed, but GlassMaterial is still mentioned in qmldir file. It shouldn't be there.

To be able to later extract the added component successfully, dependent types should be in qmldir file, so just not adding them there is not a correct solution. They just need to be properly cleaned up when depending component is removed.