Finally finished, this is what I love doing. Thanks to all at the CORE4D for pointing me in the right direction with some of the problems I had, you know who you are.
Your feedback would be much appreciated, (but be gentle)
Btw, this is a superb plugin. It scans a folder with PBR-maps and generates a tidy Redshift-shader with 1 click. It saves tons of time and includes some comfort-nodes in the shader-tree:
https://danielsian.gumroad.com/l/redshift_pbr_material