@silverpill
DIDs are built from permanent identifiers: a public key, a URL, or an address of a record in a distributed database. I don't know if Zot and Nomad have that.
Zot and Nomad have permanent identifiers that are based on public keys. In the database, the user's identity is stored as a hash. Currently, the key pair and hash never change for an identity, but the URL and address can change. The primary URL and address tell you what server is authoritative and where to send messages.

And since Zot and Nomad allow you to have clones, as long as your message is signed with the correct keys, it is considered you, regardless of which clone (domain name) that you posted from.

If you wanted to be able to rotate or change keys, an authoritative server would have to tell you that the old key and new key are equivalent and the same identity. And then your software would need to be able to recognize that.