Neither does fedimint's ecash. The client associates the notes it holds with a federationId and can change that association the same way you do with the mintUrl.

It's more complex for the fedimint guardians to agree on an update to the config, creating the new federationId, but in principal it's the same. the approach to that consensus update process just needs to get agreed on and implemented as part of the next release or potentially a hotfix.