Resolution:
If this value is set to true you will see various messages for instance creates, copies, removes, ... You will not see rollback and commit messages.

If this value is not true, then you only see startup and instance start/stop entries.

With this parameter set to true, rollback and commit message are indeed not logged.  However, you do get additional messages e.g. instance creates, copies and removes.

In Administrator 5.0, which will succeed Repository, "repo.logOperations=true" will cause commits to log a description of the node names that are added, changed or removed.