If you create a system record and associate it with a profile and then within koan you do a replace self, or specify the system record, after kickstarting the system will register again and not use the existing system profile.
1. Register a system
2. enable provisioning
3. go to provisioniong tab, select a profile and click "create cobbler system record" (This button will be going away)
4. on the client run "koan --replace-self"
5. reboot and let the kickstart go
6. see a 2nd profile register
Actually this was a missunderstanding. Not a bug!