Block a DNS server bby RPZ in Bind like:
*.dns.examplse.net.rpz-nsdname CNAME .
And for Powerdns do
pdnsutil add-record rpz.mypdns.cloud '*.dns.examplse.net.rpz-nsdname' CNAME 345600 .
Note
The empty empty_dns.list is simply to satisfy the scripts/build.sh