Hi,
I’m trying to figure out what the new Weighted Smooth Mode number 9 - Groups Intersection - does. It seems to be doing the same thing as 6 - Groups Border.
I thought maybe it’ll work on intersecting meshes within one subtool, but alas it doesn’t do anything new that I can see.
cheers
Rafal
From ZBrush Docs
Smooth Brush: New Tangent Mode
A ninth setting has been introduced for the Brush >> Smooth Brush Modifiers >> Weighted Smooth Brush slider. When the value is set to 9 this enables the new Groups Intersection mode.
This mode will affect PolyGroups which are close to each other, when their borders are parallel with multiple edge loops and will prevent these PolyGroup borders from shrinking.
Lol, thank you @zber2 !
It would seem my search skills are null 
Have a nice rest of the weekend.
cheers
Rafal