Hardware Media Encoders/Decoders when Bypassing iGPU

Seeing how the pascal laptops are only now starting to trickle out, I'm considering waiting till ~January to upgrade to wait for Kaby Lake, especially since CPU performance is important for me day-to-day. Besides the 'regular' 10% performance improvement that comes with Kaby Lake over Skylake (from the increased clocks), the main attraction of Kaby lake (cause who knows about Optane) is the added hardware decoders/encoders for media content (like 4K playback).

The laptop I'm considering comes with a 1070 with gsync, so no optimus (and not even a mux to switch). So my question is, will a machine with Kaby Lake be able to leverage the extra hardware encoders/decoders when the iGPU is bypassed and instead the dGPU is used, or will all that fall to the dGPU or CPU? Unfortunately, I don't know where on the chip the media block is with the hardware encoders/decoders, nor how its use is affected when the iGPU is not used.

I would think this should be well known for desktop users, since I'm guessing most would disable the iGPU (prolly via BIOS) and only run on the dGPU...... so the question is similar there, do you still get the benefit of the CPU's hardware media encoders/decoders? With that said, not sure if one would really care on a desktop since Power draw isn't that big of an issue since you're not running off a battery.