ELM server rename - exclude a registered application

why would you want to do that?

As far as I can tell, the only rule is that the application is accessible using its public URI root. If you only change the public URI for a part of the registered applications, the mapping file would have to be created that way. There have been/are deployments out there where one or more registered applications have public URI roots different from the JTS. So I think this should be possible. We just do not cover such exotic scenarios in the topology examples.