I've actually found GA finally fixed searching for apps on Android TV. The Play Store search is still garbage but at least voice searches return more apps now.

Try switching your language to US Virgin Islands. That will give you Google Now back on a phone, it might be worth trying to see if it does the same thing Android TV.

I'd like to go back to Marshmallow. None of the updates have brought anything of value, and CEC gets more busted with each one.

Can't you just turn it off?