Lost bookmarks after change of authentication method

We are using version 9.2 of Identity Manager and still using the Web Designer Web Frontend. We are currently migrating from NTLM AD Authentication to OpenID, this works flawlessly, but the users will loose all bookmarks they have created with the old login.

Is there any chance to copy them over or just leave them active? It the same user/identity that is connected, so where are these bookmarks saved?

Thanks in advance