Hi Mark,
Actually, it looks like syslog-ng 3.0 was released already...
A test box didn't fall over immediately upon changing the host file entry. And you'd leave tmm listed as a host for 127.2.0.2. It would just mean that 127.2.0.2 ad the other tmm IP's wouldn't have tmm listed first. I suspect this wouldn't cause any issues, but it would make sense to double check this with F5 Support. They'll probably tell you it's not a supported change. But if you explain why you want to do it, they might be willing to check into any possible problems with it. You could open a request for enhancement at the same time asking them to include the hostname for all loopback IP's.
Aaron