This is pointless hairsplitting. RFC7686 is a DNS RFC, one that specifies and enables special application handling when stipulated conditions are met. Even if

This is pointless hairsplitting. RFC7686 is a DNS RFC, one that specifies and enables special application handling when stipulated conditions are met. Even if HTTP/3 defined its use of DNS records adequately, the special case still takes precedence and onion routing continues to occur in browsers supporting it. In my view the use of a special-case TLD is deeply problematic since it contains the potential to leak your use of Tor via applications or resolvers that do not grok the exception, but that's a design problem for another day. The problems with using host address records for service location are multifaceted but the most significant are a) their conflict with other services at the same label, most commonly when the web hosting requires a CNAME, which cannot co-exist with any other record, and b) they're crude; full-grown origin discovery could support priorities, fallbacks, protocol upgrades, variation by transport, alternate ports and more besides.