You would need to hardcode the IP address everywhere it's needed and you would need to release an update every time you want to make changes to it, right? That

You would need to hardcode the IP address everywhere it's needed and you would need to release an update every time you want to make changes to it, right? That doesn't sound like a thing anybody would do. Also, people using DNS level ad-blocking are rare and loosing that kind of flexibility just to make life harder for such a small amount of people doesn't really make sense.