The debug log shouldn't show anything regarding that as those are defined settings/outputs of the different passthrough transcoding programs.
As for the file you're trying to stream, since it's H264 (x264 is just an H264 encoder) with DTS, the new PMS 1.10 release (due out soon) should be able to handle this with just a remux and no need for the CoreAVC-CUDA GPU help. The link to the Win 1.10RC installer can be found here: viewtopic.php?f=2&t=675&start=120#p4193.
My understanding is that Avisynth/FFMpeg is really only used for enhanced subtitle support. If the other engines are working fine and there are no subtitles with this file, is there another reason why you want to use Avisynth/FFMpeg?