I worked on some test environment for an upgrade of the LibreOffice extensions and templates websites to the latest Plone 4 version during the last week. I had to find solutions for some issues. In the end the upgrade in my test instance were successful.
I worked on the current LibreOffice extensions and templates instance with my experience, that I got from the test instance today. I upgraded the Plone buildout from version 4.2.6 to 4.3.9. I had to fix an unexpected error during the upgrade of the instance zope database. Apart from this the upgrade runs smoothly. The LibreOffice extensions and templates websites are up again, running on Plone 4.3.9 for now.
The next step will be the change of the multilanguage framework to a newer Plone add-on.