any new recoveries?

[xd4d3v]

just tried installing magisk on oreo, and twrp cannot mount /vendor.
I suspect it's a twrp rather than magisk.

are there any other newer recoveries I can try?

 

[Mogster2K]

IIRC the Magisk app can modify a boot image for a different device, so you could use Magisk on your phone to modify the Shield TV boot.img and then flash it with fastboot. Also, last time I checked there was a Magisk 16.4 beta for Oreo.

 

[Quietsch]

just tried installing magisk on oreo, and twrp cannot mount /vendor.
I suspect it's a twrp rather than magisk.

are there any other newer recoveries I can try?

you have to flash a new boot.img.
Here a link. Just done it yesterday. Dont forget to install the Magisk App after reboot.
http://www.videomap.it/forum/viewtopic.php?f=25&t=1646&start=1770