You don’t even need to take Android TV offline. Just replace the ad-ridden launcher with ATV launcher, and remove the default one with adb. Also replace the youtube app with SmartTube. Very happy with this setup.
I didn't even bother using ADB with Projectify launcher from the Play Store (it just has a couple settings I needed to enable to take over the home button) and I haven't seen the default launcher once. I am using an Onn Pro 4k on my main TV (for Ethernet) and CCwGTV on the others.
Incredibly snappy setup with detailed customization options, I switched all my TVs over to use it. I also recommend Button Remapper to customize the remote app buttons to your liking.
Incredibly snappy setup with detailed customization options, I switched all my TVs over to use it. I also recommend Button Remapper to customize the remote app buttons to your liking.