Vizio 4K 60 Hz HDMI support?

So I bought a Vizio 4K 60Hz TV (model D40U-D1) a while ago and have been struggling to get 60 Hz at 4K out of it with a 4 GB EVGA 960 GTX card. Works out of the box on Windows, but is stuck at 30 Hz on Linux. Someone started a thread discussing an almost identical problem here a while back, unfortunately to no resolution: The guy who started that was good enough to be very detailed in his description of the issues being experienced.

Anyway, after extensive testing, thinking the issue was the Linux Nvidia drivers either not supporting YCbCr420 chroma subsampling, or just not properly supporting 4K at 60 Hz over HDMI2.0, I finally got my hands on a friend’s Hisense 43H7C2 4K TV. With that, I was able to get 4K@60Hz over HDMI2.0 no problem (wouldn’t recommend that TV as a monitor though; image quality is pretty terrible).

I found other people complaining about issues with Vizio TVs and 4K here throughout the forums, so I’m guessing it’s pretty safe to say this is a Vizio specific issue.

Could some of the Linux driver devs provide some help here? I can post debug logs or anything needed to help resolve the issue. If the Linux driver development is done in the bay area, I can literally drive the TV over to the Nvidia offices if that makes debugging things easier, haha.