Internal classes behave differently with regards to iControl. If you use the API to make changes to a internal class, then change is resident in memory (not in the disk configuration) until you issue a ConfigSync.save_configuuration() call. This will flush the config changes to disk. After that you can call load_configuration() to reload it but it is not necessary. We chose not to automatically flush all API calls to the disk's configuration because the time it took to do so for large configurations caused problems for apps making large number of calls. We chose to make it the users choice when the config was saved.
-Joe