It´s probably the method with adding procedural textures on a Group/Folder and 0 out the channles you do not want. An Example file is attached. There is sadly no explanation given regarding the handling of the Alpha texture or how to export it so it works.
This channels issue is totally no problem for me. You just have to start with a transparent document and then could work in any of RGAB in main layer stack having a special group for each of RGBA. They did very cool links panel that could link many parameters in between layers providing shared masks for example but for…
Photoshop still could be used in modern texturing pipline as a texture mixer / compositor. You can do action/script that could make one click 'height blend' masks stack and keep normal,roughness, depth 'channels' inside switchable smart objects and layer compositions . With a bit of java scripting you can automate the…