script to migrate users from old user management tables to a DELEGATED directory

A way to migrate users from old user management tables to a DELEGATED directory to allow upgrades of systems connected with Large LDAPs that fail during the upgrade.

When the upgrade for customer with Large LDAPS is not possible?
If the previus version use atlassian-user (hibernate) LDAP and it is a large LDAP -> It fail because the type of directory created will be CONNECTOR and it tries to syncronize during upgrade.

What would be a quick patch solution for now?
1) we not copy atlassian-user.xml file over the new installation during the upgrade.
2) new Confluence will think there is no LDAP and will simply copy over the old user/group related tables (external_), not move the data to the new cwd_ tables unless for the Internal Confluence users.
3) After the upgrade is sucessfull, we will be able to log on with a Internal Confluence admin user and create a new DELEGATED directory
4) we should have an option to run a script to move of all data from deprecated tables to the DELEGATED LDAP directory (users, group and memberships)