The Growth team plans to move configuration of Growth Experiments as part of T274520: Move Growth configuration to on-wiki JSON file. The configuration is stored in server configuration right now. We should have a way to easily create config files, using the information from server config, to make it possible to easily migrate any number of wikis.
There will be a maintenance script that can be executed from the maintenance server (mwmaint1002), which will look into current server configuration, and copy all variables that should be managed on-wiki to the on-wiki configuration file. The script will attribute this edit to a system user, MediaWiki default, to make it clear it is a standard part of software development and not an action of a particular staffer.