Your answer is what I have been getting across the internet except that link I posted in OP. It has been driving me crazy for months. I finally decided to buy the Sonos ARC to confirm this myself. The short answer is actually, Yes, the C8 can convert TrueHD to DD+ and send it via ARC to Sonos ARC. However, the native LG Plex app can’t do this. The content needs to be external. See this post: Plex on LG C8 can't convert TrueHD to DD+ but if played through Shield TV Pro, it can
