Is this for the "Alloy" asset store package?
Yes. You add this node to the end of your .sbs graphs to output correctly for the Alloy plugin shaders, including Packed Map output etc. I use this node for the Substances in my packs on the Unity Asset Store.
Hey, I was wondering if there are any way to get full benefits of packed maps by using substance designer? I've created my own node before, but I also noticed that alloy can do some "anti-aliasing" magic by combining alloy packed map's channels + normal map.
I can't preview your node right now as I'm at office, but I assume it just simply blends (combines) the required channel to one alloydm channel.