Thanks for the clarification – this is super helpful. I think conventions can be really powerful, and often overlooked, and I am glad that at least in the naming scheme PBRs are converging.
What I found confusing when using the Bella PBR is that it doesn’t let you know it has sucked in the other files, at least in the Rhino plugin interface. I figured it out by rendering a few materials from cc0textures.com (thanks for the pointer), and seeing that things were happening. I tried using the Rhino PBR, and the Bella PBR – Bella looks much nicer!