Automatically create non-existent users in Delegated Directory

I've been testing Crowd 1.3, and I really like the new Delegated Directory feature. One thing I found non-obvious about it was that users have to be manually created or imported in the delegated directory in order to be visible, even if they actually exist in the underlying connector-based directory. It would be nice if there was a way to have the Delegated Directory have a fallback when a user isn't found in the internal directory, which is to check in the connector-based directory and if the user exists in there, to create it in the internal directory.

One important advantage of such a fallback is that users wouldn't have to be created in two separate places - Crowd would automatically know about a user as soon as it was created in LDAP. (With the Delegated Directory the way it currently is, the user might exist in LDAP but not be visible in Crowd.)