Ignore Unused Materials not working?

[creyes]

What does "Ignore Unused Materials" actually do? I've got the "Ignore Unused Materials" option checked in my general settings, but every time I resend a scene to render all the materials in the material manager get exported, even if they're not applied to any objects or if they're hidden from the material manager with a layer. If I've got a simple scene with 20+ complex materials in it, I have to wait upwards of 30 seconds for octane to export all the materials that I'm not even using.

[aoktar]

It's for Picture Viewer rendering. It does what the word describes.