Firstly, thanks so much for putting all of this information together ... super helpful!
I'm currently reviewing PBR Part 2 (
https://academy.substance3d.com/courses/the-pbr-guide-part-2) and under the Specular/Glossiness workflow, the "Glossiness (Grayscale - Linear)" example image seems to contradict the written text; I suspect the text is correct and the image was accidentally copied from the Metalness/Roughness workflow.
Cheers and thanks again!
-H
