I’m not the person you replied to, but I think my experience could be relevant.
I have a MiBox TV S 4K, which as far as I know runs pretty pure AndroidTV (but I might be wrong). This is still going to try to connect to Google and Xiaomi servers for tracking and ads… but I have set up a custom DNS blocking trackers and ads.
I found this Reddit post and followed the instructions to change the DNS server on the MiBox to NextDNS, where I could later activate relevant blocklists (SmartTV, Xiaomi, Google). I also perform monitoring of the domains the MiBox connects to and have blocked a couple manually.
Finally, for AndroidTV forget about NewPipe and use SmartTube. It’s the same idea, but optimised for the AndroidTV experience where you have a remote and not a touchscreen.
Glad that I could help. If you need help with setting the custom DNS or choosing which domains to block feel free to ask me here.