Now I don’t know whether this is possible but can’t hurt to dream. But I would love to use ATV 4k as a PMS and not just as a PMP with my NAS drive serving as the storage. My understanding is that it has just as much grunt if not more than the nvidia Shield.
I would only use my NAS as PMS! Sorry couldn’t resist, said tongue in cheek. 
I wouldn’t enjoy this, ATV 4K would need some power up elements for other clients to connect too, locally and remotely. It wouldn’t have enough grunt for my household use either. Kids all streaming at the same time, mum and dad too.
I doubt very much Apple will open up their box of tricks to enable this feature either. Different ball game when compared to Nvidia.
But I think the Apple is more powerful, yes?
Quote from androidcentral…
Another area that’s close, but ultimately where Apple takes the win, is when comparing the A10X Fusion chip with the NVIDIA Tegra X1 processor. While the X1 is still a fantastic, dynamic and gaming-focused piece of silicon, the A10X has it beat for absolute power and GPU performance, and that may count for something if you take your gaming seriously._
