I may have simply missed it in this thread but why is no one simply using this:
https://xdaforums.com/fire-tv/general/ftvlaunchx-custom-launcher-root-t4037397
@SweenWolf on the Fire TV Forum even created an ATV Launcher for the Shield TV. Which is what I use. U just install FTVLauncherX and then his WolfLauncher and it works really well. Also with FTVLauncherX you can use whatever app you want as a launcher.
I imagine most users find using ADB pretty daunting. It's a wonderful thing but then I started in DOS. Especially now that one can cut and paste from Windows to a Command Prompt.