i did diablo III two days ago so i know it works. it dosnt matter from where you launch it, if you are using steam/gog/bnet you will have that up and launch whatever game through that, thus you cant start diablo III without opening the bnet app (bnet.exe) and pressing Play then Diablo will run and the sweetFX should be on. it will work as long as you put the SweetFX in the proper game folder next to the .exe. dont matter how it launches as long as the sweetfx in the right place. hope this cleared that up for you :)