Migrate from internal to external LDAP providerr

is it possible to switch to an external LDAP provider while keeping user content?
For example I have created a user account “emily” while using the internal LDAP provider. However when I switch to an external LDAP service and log in again with the same UID “emily” there are no files. I assume the problem is that the accounts have differnet UUIDs, but I’m not able to adjust those. Is there anything I can do to migrate the external user accounts? I’ve seen the posts abouting migration in OwnCloud 10. However these I believe require commands not available in OCIS. Furthermore when running with external LDAP I’m not able to see the “old” accounts in the Users Tab.

As external LDAP service I’m running LLDAP while basically using the example config for OCIS taken from the projects example configs.

Afaik there is no migration path for that. You might have to do this manually.