I did a Google search and it seems optical cannot even carry Dts master or true HD. However, Don't quote me on that.So the best way to go is to get an optical cable. Does that pass bitstream to the AVR so that if it has ATMOS encoding it will pass through?
Also, 99% of the time I'm only using the TV as a video player with all sources going through my AVR. What do you have to do to switch from just streaming the video from my AVR to the TV to streaming the video and audio from my TV to the AVR (ARC).