Doesn't remote play work on PCs now? Wouldn't you just add that remote play application to your "games" list and use Gamestream to get it on your TV?

I got this working.

I followed this root tutorial: http://nvidiashieldzone.com/shield-android-tv/android-7-nougat/tutorial-root-shield-android-tv-2017-16gb-nougat/

except, when you get to the step to flash SuperSU I flashed Magisk.

I used the newest Magisk zip from here: https://forum.xda-developers.com/apps/magisk/official-magisk-v7-universal-systemless-t3473445

TWRP i used the 6/25/17 img from here: https://dl.twrp.me/foster/

After rooted and you are back in Android TV, I followed these steps for Remote Play:

https://www.xda-developers.com/how-to-enable-ps4-remote-play-on-any-android-and-play-dualshock-4-tips-opinion/

I installed the Remote Play 2.0 APK manually from the file on APKPure: https://apkpure.com/ps4-remote-play/com.playstation.remoteplay

I did install Sixaxis Controller app, but I couldnt get a PS3 controller to control the PS4 via remote play at all. It would control the Android TV interface, but it did nothing inside of Remote Play. PS4 controller worked fine though, although I did have to create a new user (as detailed in the XDA guide) to be able to use it.

BTW, to make a USB Male to USB Male, I just took two old USB to mirco usb cables and hacked off the micro usb ends and soldered the wires from each together. Worked just fine, and over USB 2.0 as well.

So you first have to root the shield TV which I've found to be a bit more difficult than usual since you need to connect the shield to a computer and you need a specific type of cable (plus not all brands work). I just rooted my k1 and connect to the TV via mini HDMI, it's nowhere near ideal as what it used to be and I wish either the dev would realize he left a void, or Sony would give us something official