Yes I understand that, the only problem is that the roughness also changes the transparency glossiness. If I move the roughness closer to 0, my wax looks like glass. It would be best to separate the transparency roughness from the reflection roughness. Or is there a way to do it with a mix material ? I didn't seem to make it work as the mix material doesn't seem to allow me to add a reflection layer as the blend material would in vray, which is kind of a lack to simulate wood materials or car paint material with multi layered coats.
Another point, I think namings are a bit confusing in octane. Specular material for a transparent material does not make a lot of sense to me. Why not calling it transparent material ?