Reproduction steps:
1. Open the project from the attached file "1238204.zip"
2. Go to Layers(upper right corner of the Editor) and select Nothing
3. Inspect the Scene View

Expected result: Bones of the Bone Renderer are not visible in the Scene View
Actual result: Bones of the Bone Renderer are visible in the Scene View

Reproducible with: 0.2.1(2019.3.14f1, 2020.1.0b9, 2020.2.0a11), 0.3.3-preview(2020.1.0b9, 2020.2.0a11)
Could not test with: 0.1.2, 0.1.4(bones are not rendered in the Scene View), 2018.4.23f1(no Animation Rigging package)

Note: When changing Layers to Nothing and then back to Everything a script icon appears near the rendered bone until GameObject is selected.