I used the Sunday morning to upgrade my Baïkal instance to version 0.11.0 (if you experience issues with the MySQL connection afterwards, make sure to add the new required configuration entry mysql_ca_cert to your config).
And I also used it to enable CardDAV (previously I solely used it as calendar via CalDAV) and moved all my contacts from iCloud to my own server. This was not as easy as first thought, since importing a list of vCards in the macOS “Contacts” app won’t sync all of them. I ended up using my iPhone to import all of my contacts to my own server.