I don't get it.... Why don't you just take BB's advice instead of fiddling around? Use the proper PP2012 scatter nodes and get rid of the old workarounds like Fastscatter (which was invented to deal with the fact that Poser didn't have scatter). I NEVER see this effect, and I render with IDL all the time. But I don't use Fastscatter (and only rarely use Translucence).

______________

Hardware: AMD Ryzen 9 3900X/MSI MAG570 Tomahawk X570/Zotac Geforce GTX 1650 Super 4GB/32GB OLOy RAM

Software: Windows 10 Professional/Poser Pro 11/Photoshop/Postworkshop 3