Original text:
4. When a DNS client is configured with an Unencrypted Resolver IP <del> address, it SHOULD query the resolver for SVCB records for "dns://resolver.arpa" before making other queries.  Specifically, the </del>  client issues a query for "_dns.resolver.arpa" with the SVCB resource record type (64) I-D.ietf-dnsop-svcb-https. If the recursive resolver that receives this query has one or more Designated Resolvers, it will return the corresponding SVCB records. <del> When responding to these special queries for "dns://resolver.arpa", the recursive resolver SHOULD include the A and AAAA records for the name of the Designated Resolver in the Additional Answers section. This will allow the DNS client to make queries over an encrypted </del>  connection without waiting to resolve the Encrypted Resolver name per I-D.ietf-dnsop-svcb-https.  If no A/AAAA records or SVCB IP address hints are included, clients will be forced to delay use of the a mode in which clients do not validate the name of the resolver presented in the certificate.  Opportunistic Privacy similarly applies to DoQ RFC9250.  A client MAY use information from the SVCB <del> record for "dns://resolver.arpa" with this "opportunistic" approach (not validating the names presented in the SubjectAlternativeName field of the certificate) as long as the IP address of the Encrypted Resolver does not differ from the IP address of the Unencrypted Resolver.  Clients SHOULD use this mode only for resolvers using private or local IP addresses.  This approach can be used for any encrypted DNS protocol that uses TLS. </del>  5.

Reviewer comments:
There is no need to use a DNS URI for this. You are only using the name. And you don't cite RFC 4501. It is also incorrect, because you are treating "URL" as the authority, rather than the qname. What you really want is "URL;type=64" or something like that. But the words you have are adequately clear.

Revised text:
4. When a DNS client is configured with an Unencrypted Resolver IP  <ins> address, it SHOULD query the resolver for SVCB records for the name "resolver.arpa" before making other queries.  Specifically, the </ins> client issues a query for "_dns.resolver.arpa" with the SVCB resource record type (64) I-D.ietf-dnsop-svcb-https. If the recursive resolver that receives this query has one or more Designated Resolvers, it will return the corresponding SVCB records.  <ins> When responding to these special queries for "resolver.arpa", the recursive resolver SHOULD include the A and AAAA records for the name of the Designated Resolver in the Additional Answers section.  This will allow the DNS client to make queries over an encrypted </ins> connection without waiting to resolve the Encrypted Resolver name per I-D.ietf-dnsop-svcb-https.  If no A/AAAA records or SVCB IP address hints are included, clients will be forced to delay use of the a mode in which clients do not validate the name of the resolver presented in the certificate.  Opportunistic Privacy similarly applies to DoQ RFC9250.  A client MAY use information from the SVCB  <ins> record for "resolver.arpa" with this "opportunistic" approach (not validating the names presented in the SubjectAlternativeName field of the certificate) as long as the IP address of the Encrypted Resolver does not differ from the IP address of the Unencrypted Resolver. Clients SHOULD use this mode only for resolvers using private or local IP addresses.  This approach can be used for any encrypted DNS protocol that uses TLS. </ins> 5.