In templates/dnsdist.conf.j2 newServer is defined as:
newServer("{{server}}")
This makes it hard to add additional configuration like QPS or pool, removing the '"' and defining server as:
"{address='1.1.1.1', pool='testing'}"
Made it possible.
Not sure if there is a good reason for using the '"' in the config, but wanted to file the issue to find out