Exactly 😄 - however, since the server uses pyhocon to parse those vars (that's why you can provide an entire structure there, not just text), make sure to provide a value that can actually be parsed as such (i.e. the string the server should receive for each "connection" should be something like
{hosts: [{host: "127.0.0.1", port: 9200}], args { timeout: 60, dead_timeout: 10, max_retries: 3, retry_on_timeout: true}, index_version: "1"}etc, and NOT
"{hosts: [{host: "127.0.0.1", port: 9200}], args { timeout: 60, dead_timeout: 10, max_retries: 3, retry_on_timeout: true}, index_version: "1"}"