[ignoramous]

> A cross-organizational fallback is not possible with DoH in many clients, but it is with plain old DNS.

That's client implementation lacking, not some issue inherent to DoH?

   The DoH client is configured with a URI Template, which describes how to construct the URL to use for resolution. Configuration, discovery, and updating of the URI Template is done out of band from this protocol.

  Note that configuration might be manual (such as a user typing URI Templates in a user interface for "options") or automatic (such as URI Templates being supplied in responses from DHCP or similar protocols). DoH servers MAY support more than one URI Template. This allows the different endpoints to have different properties, such as different authentication requirements or service-level guarantees.

https://datatracker.ietf.org/doc/html/rfc8484#section-3

[lxgr]

Yes, but this restriction of only a single DoH URL seems to be the norm for many popular implementations. The protocol theoretically allowing better behavior doesn't really help people using these.