I am also using the Substance plugin from Market in 4.8.
My locations were different than posted. (Notice the UE4 dir)
###Development
32bit
\Epic Games\4.8\Engine\Intermediate\Build\Win32\UE4\Development\Launch
64bit
\Epic Games\4.8\Engine\Intermediate\Build\Win64\UE4\Development\Launch
###Shipping
32bit
\Epic Games\4.8\Engine\Intermediate\Build\Win64\UE4\Shipping\Launch
64bit
\Epic Games\4.8\Engine\Intermediate\Build\Win32\UE4\Shipping\Launch
Though it only seemed to be the 64bit ones that were missing.