Here is a tip off the back of the advice given to me above about sideloading apps.
You can sideload an app called Smart Youtube TV to watch YouTube without ads before and during videos.
This is available to download from
the Smart YouTube TV Github page.
To install it, you need to:
- Download the "stable release" from the Releases page of the link above
- Copy the .apk file to a USB drive, or save it to your Google Drive/OneDrive/Dropbox
- Download and install a file explorer app from the Play Store on the TV itself (I used Solid Explorer but there are various available)
- If using a USB drive, connect it to the TV; then open the .apk file in the File Explorer and install it (you may need to enable installation of apps from the app in question if prompted)
- You should now have the Smart YouTube TV app listed in Apps
- When you open the app, you can sign in with your Google account details
- You now have the ability to watch YouTube on your TV without ads.
Hope this helps someone!