It seems Oracle has lost all interest in its on-premises software. I’ve noticed this with other features and behaviour changes, this is just a small example.
Remember the article about DBCA silent installation? I mentioned the following:

• Controlfiles are not multiplexed to different paths as specified. First given path is used for all controlfile members (SR is "Work In Progress")

Last Thursday, after 3+ month, my Service Request has finally been updated with an answer. They’ve changed DBCA to ignore the <ControlfileAttributes> section and the CONTROL_FILES “initParam” value unless you specify “-honorControlFileInitParam” argument. This argument does not show in the dbca help “dbca -createDatabase -help” nor is it anywhere in the documentation – how I’m I supposed to know?. And this is what bugs me the most: Oracle 12.2 on-premises is out now for quite a while but it seems that the documentation has not been updated in many places. Guess that’s how it’s gonna be from now on 🙁