[Shield Android TV General] Downunder35m:
I think I am able to shed some light onto the confusion why it works fin on some devices while failing on others, or better why it fails on the 2017 models.

ACIDxCHRIST did what I did myself, and we all get exited if we get root on a new system.

And once we do and can istall and use root apps all is fine.

Only difference was that I tried right away to pull images and modify the build.prop, which all failed.

Anyway, the Darcy models use a standard fstab file plus a USB FSTAB file.

The system partition is only listed in the later and some partitions have different flags as well.

And as the userdata is subject to encryption that the new bootloader enforces hard we had to keep dm-verity enabled.

The Magisk version Whiteak posted works fine from my tests on 7.2 - with dm-verity enabled but not all write access works yet for me.

I had a massive stuff up with the DTB solution he posted so I have to find a way to start from scratch now thanks to trying the 7.2.2. update manually.

What I can not stress enough about after my self created stuff up:

DO NOT DOWNGRADE FROM 7.2.2. WITH THE FLASH-ALL.BAT!!

I guess same is true for the 7.1.1. but I did not try it.

Some firmware updates contain a blob - this is the bootloader.

I messed up here at some stage and that caused a massive failure that I sturggled to fix.

A lower bootloader is not able to handle the partition info on the device.

Unlike updates for other devices our partitions are not wiped or formatted before the flashing.

Nice to keep your apps and settings, bad if there is a real problem.

In the worst case (maybe mine) it becomes next to impossible to enter the bootloader mode.

Rooting by be a pain in the behind and we now know that even Nvidia bends down to Google demands in terms of not allowing the normal root procedures stated with their 2017 model developer updates.

It simply is a false statement!

SU is not update for this type of kernel security and Magisk even needs tricks to work with it.

I strongly suggest that anyone who does not really need root simply sticks without it.

We will continue to find ways to get full root in a fully safe way and what is posted so far by me and Whiteak is confirmed.

All devices apart from Darcy should have no real dramas with TWRP either.

A simple port like discribed

here

should work for them.

Only have my Darcy so my testing is limited to this model.

Oh... : If people like the op here would not post things like this then we would never learn anything ;)

Just check how many people only want root but have no clue about the required procedures.

We got dependent on easy and click to use rooting tools and the people still trying to understand how new firmwares work are dying out.

Devices sold by the millions still see developer support but a Shield or those new VR headsets are nothing these guys bother with.

Even if you are impatient, don't jump onto everything you see in the first post of a thread.

If it updated then check the last pages of the thread to see what users posted about it ;)

So lets just work together, do the test we need, compare results and last but not least hope that Nvidia changes their ways back and soon provides full kernel sources for the 7.2.