Resolution:
One major reason that they need to have the same name is that if there are servers with a route to this FT server, they expect to connect to a server with a given name.  If, on failover, the name changes the other server won’t connect the route.

Another reason is that the intent of an FT pair is to emulate a single server.  If it is changing its name from time to time, that does not emulate a single server.

Finally, we don’t test this configuration and don’t support it so why would you want to do this?  We don’t see any advantages.