4censord on Nostr: prettygood for synapse, I can tell you, for the others I do not know. Deprecation ...

prettygood (nprofile…pl7n) for synapse, I can tell you, for the others I do not know.
Deprecation should be as easy as adding it to the config file of the new one.

For synapse, its documented here: https://matrix-org.github.io/synapse/develop/usage/configuration/config_documentation.html#signing-keys