It seems facesets do not handle other shaders apart from katana_default. Even if a custom shader is added (e.g. a shader that always paints green), it will be ignored.
Steps to reproduce (option 1):
Load attached project (which is an example of a katana_surface shader being applied to either a primitive or a faceset), and the texture floor.jpg.
Expand all.
Toggle between the two terminal nodes.
The texture will only be visible from the first node (when it is assigned to the primitive), but it won't be visible from the second node (when assigned to the faceset).
Steps to reproduce (option 2):
Create a custom shader by downloading green.glslfx (attached) and placing it into a KATANA_RESOURCES/Shaders/Surface/ folder.
Load attached project (the same as in option 1).
Edit the Material node and select the green.glslfx shader (you may need to reload shaders if it does not appear on the list).
Expand all.
Toggle between the two terminal nodes.
The green color will only be visible from the first node (primitive), but not from the second node (faceset).
Acceptance criteria:
Faces mode should take priority over facesets with materials (or VOS).