No worries. So, when you enable 'external player' in ZDMC, all it's doing is acting as the front-end to manage your movie/TV library (posters, fanart, metadata), while pushing the actual playback to the native/external player that has better PQ and can render 3D MVC. Plus 4K at 10-bit.
I'm unsure if you disable 'external player' and just use ZDMC (and its internal "dvdplayer") whether it can render 4K at 10-bit. It however can pass HD audio, but not 3D MVC like I said.
So, if you do settings like I have in the pictures in post #1, you will get the best PQ, AQ, 3D and 4K playback out of X8 and X9S. With 4K, HDR and color space, there are some issues that @
wesk05 and others have mentioned that Zidoo needs to fix or improve, but generally leaving at 'Auto' works fairly well.