After much loss of hair (from pulling it out trying to nail down this problem), I have figured out that there is a bug in OctaneRender's support for LightWave "Compound" nodes: you cannot rename the outputs for materials, or OctaneRender ignores them.
(EDITED TO ADD: I just discovered that you cannot rename the inputs to Compound nodes either, if they are OctaneRender materials. But frankly, I'm exhausted from figuring out the output problem and writing this up; you'll just have to take my word for it: you can't rename inputs OR outputs on LightWave Compound nodes if the inputs or outputs are OctaneRender materials.)
Below are screenshots that illustrate the problem. What you see below is a simple model with a flat green base material ("Principled BSDF" for LightWave, "Diffuse Material" for OctaneRender). The models use edge shading ("EdgeShader" for LightWave materials; "Dirt Texture" for OctaneRender materials) to show "dirt" and "worn edges". For ease of viewing, I've made the "dirt" blue and the "worn edges" red (and again, using "Principled BSDF" and "Diffuse Material" for LightWave and OctaneRender respectively).
The edge shaders and the materials that comprise the edges and corners are placed in a standard LightWave "Compound" node so that they can be reused more easily across my model. (NOTE: The actual "Compound" nodes in my model are much more complex than this with several inputs that control how they work and many more nodes inside the "Compound" node; that's why it took a while to nail this problem down. I've cut down the example to the bare minimum to illustrate the bug at hand.)
Everything worked great in OctaneRender--at first. Then I started trying to reorganize the node names to make them easier to reuse, and all heck broke loose. Behold:
I have attached a zip file to this post with the three example scenes and objects that demonstrate the problem.
Assuming that this is a bug in OctaneRender (and not a limitation of the LightWave SDK), it would be appreciated if this could be prioritized for a fix in the next release of OctaneRender. Not being able to rename the outputs from Compound nodes severely limits their usefulness when the nodes can emit more than one material. Thanks!