You're going to lose this cat-and-mouse game, it's the same one that gets played with malware C2 domains (except it's worse because both the proxy operator and the actual domain operator are colluding). Add in the zero-cost nature of subdomains as opposed to needing to pay for new DGA root domains and the fact that they can run the whole thing behind e.g. cloudflare to prevent IP blocking? Forget about it.