the radius plugin is capable of writing out these files - if the IP address is associated to the user name in the radius backend then the plugin can write out this file.
The proper solution is , indeed, to move routes which need to be pushed to all clients to the main server config.
Also note that it is possible to include config files into config files, e.g. inside 'server.conf' use
config global-routes.conf
this way you can keep all global routes in a single config file.
