Roughness values should always be in linear space - you will get inconsistent results with sRGB. In terms of reference, have a look at this: https://seblagarde.wordpress.com/2014/04/14/dontnod-physically-based-rendering-chart-for-unreal-engine-4/
Hi there. I found some very old project in my archives. I did this for Blizzard Fest Game Artisans Challenge (guess 2014). I gonna try finish this in free time.
Unfortunately, no, the Suite is discontinued software and is no longer being actively developed or maintained. To continue using it I recommend working with PS 2014 to 2018.