Hello Paride,
I've tried to do what you said in this topic but I didn't managed to make it work on Phoenix FD, I guess I'm a map channel noob
I know that it's time consuming for you as Phoenix FD is not a part of 3ds max but it is a really big industry standard now.
I'm thrilled by the work done on Octane and I'm using it for almost 10 years now and I won't see myself using another plugin but that said, we still don't have a correct workflow for wetmaps or liquid blending.