ID 378504 - 'missing' default scene items are inadvertently created when exporting to alembic via the Item List

Problem summary
When exporting selected layers to an Alembic file with the "Export Selected Layers" option, a Directional Light Locator and a Camera will also be exported, even though they have not been selected. 

If you delete any scene items except for the desired layers and export to Alembic through File > Export, the Alembic will export only the desired layers correctly.

Customer reported version
Modo 10.1v2 

Customer reported platform
CentOS 6

Steps to reproduce

1) In a new scene delete all items in the Item List.

2) Now create 2 mesh layers and create a primitive on each.

3) Select the two mesh layers in the Item List, which should be the only layers in the scene.

4) Right-click > Export Selected Layers.

5) Save as an Alembic file (abc).

6) Now create a new scene and import the Alembic file.

7) Open the group folder and notice that a Directional Light Locator and a Camera have also been exported. 

8) Now return to the original scene and export to Alembic again via File > Export As.

9) Import this new Alembic file and you'll see that only the mesh layers have been exported, as expected.

Workaround
Unknown. 

Reproduced by support

This bug has been reproduced in:
Modo 12.2v1 - Windows 10 - MacOSX 10.13 - CentOS 7 
Modo 11.2v2 - Windows 10  
Modo 11.1v1 - Windows 7 - MacOSX 10.12 

Earliest version tested
Modo 11.1v1 - This issue appears to be in all versions of the product.

Expected behaviour
Exporting selected item layers to an Alembic file with the "Export Selected Layers" option should only export the selected item layers to the file. 

Actual behaviour
When exporting specific item layers to an Alembic file with the "Export Selected Layers" option, a Directional Light Locator and a Camera will also be exported to the file, even though they have not been selected.