sorry I meant a ISO burned on a bluray disc. You can't play ISO via USB or the network on the x700.
But there is a way better solution (as long as you dont care about menu and extra).
You can use the latest tsMuxer and remux the original m2ts straight to TS (or m2ts) and the file will play in dual layer Dolby Vision + Atmos + subs on the x700.
you can add custom subtitles file as well.
https://bintray.com/justdan96/tsMuxer/t ... htly#files