I have that option.
When it's enabled, the input is not recognised by the TV when I select 4k@60hz, it works OK with 4k@30hz but I need 60hz.
When It's disabled, the screen works at 4k@60 but the screen is pink.
It's written "high speed cable with ethernet" on it. I have hunch that the problem might be the hdmi cable. I have other hdmi cables in the house labeled the same and other cables not high speed with ethernet and they all behave in the same way.
What's interesting is that at 4k the maximum I can get is 31hz. Could a 1.4 hdmi cable set this limit? If I select more hz the image looks horrible.
By now I have eliminated the problem with the laptop, I checked with 2015 mid rMBP 15" and 2014 rMBP mid 13" and they behave the same.
I know the tv has hdmi 2.0 input capable of 4k@60hz at 4:4:4 (it even shows in the menu)
The mini display adaptor from Club3 has positive feedback and it should work theoretically.
I'm going to purchase another hdmi cable 2.0, hopefully this will solve my problem.
Will get back with updates.