I note from GitHub that the default_settings.php file is being updated. IIRC, this means recreating the setting.php file to include the additional parameters / values.
Am I remembering this correctly?
If so, could a mechanism be implemented that uses the ‘default_settings.php’ and the ‘settings.php’ file hierarchically i.e. the defaults are loaded then overwritten by any values in the settings file (likely to be a subset). This is a common UNIX solution to configuration.
There are a number of historical threads here that show that updating the default_settings.php file causes issues.