For consistency, it would be nice if the PrivacyManager plugin + Custom logo ([Branding] section) stored its data in the DB rather than in the config file.
The ultimate goal is to make Piwik not need to write to the config file during normal operations.
The values from the option table should overwrite the values from the config in case the delete old data admin UI is enabled. It should not be possible to set a value in the option table while the delete old data admin UI is disabled.
Here are the config settings that, should be removed in favor of Option::
In 883ecc81b96336d3a61fb193af51ecd3fb9b6d91: refs #4563 moved custom logo from config to database
In 0e3592fcb8ab5ae3b9fa6b2a2d31304bf851211d: refs #4563 fix cached version was not used because there are more than 3 entries
In e36c5964faa34157f3b01398c997c63918d71897: refs #4563 PrivacyManager Settings should be in Config and Option table, also removed some completely from config as described in ticket
In 1d6488271e0db0d926f52e5605e641ed86e67453: refs #4563 make sure getting purge data settings works if UI is disabled
In e6af5917d7c872ccdbf7479070a2dec486df5558: Refs #4563 Hiding message that config is not writable, when writing to the config file is disabled anyway.