DU> What is a "registered name server" which you want removed?

BC> There is a free-standing A record carried by each TLD root [...]

There is no such thing as a "TLD root". It's a self-contradiction. You
mean "published by each TLD content DNS server".

BC> This provides a sort of backdoor nameservice that is effectively
BC> bulletproof. The name is resolvable even if it is in a domain without
BC> nameservice, because the TLD [content DNS servers] have that glue
BC> record.

Unfortunately, it's a hole in the RRP; that cannot be fixed unless the registry
requires everyone to employ best practice exclusively in their delegations, and
prohibits merely good practice.