> Sometimes is enough one bad actor under one of your subdomains to have a full ban on the whole domain.
If you're running independent subdomains where a bad actor on one should not affect the reputation of the rest, you probably should add your domain to the public suffix list: https://publicsuffix.org
Note that adding your domain to the PSL changes how browsers interact with it, so don't do it lightly. In particular, no more cookies for the parent domain.
If you're running independent subdomains where a bad actor on one should not affect the reputation of the rest, you probably should add your domain to the public suffix list: https://publicsuffix.org