Clojurians Log v2

I have a test setup function that I want to only execute during integration tests. My understanding is that the :test-configs key merges the config in to the project test config, so something like this in my workspace.edn should work:

{...
 :projects {"example-project" {:alias "ep" :test {:setup-fn my-org.example-project.core/integration-test-setup}}
            "different-example-project" {:alias "dep" :test {:setup-fn my-org.different-example-project.core/integration-test-setup}}}
 :test-configs {:unit {:org.corfield/external-test-runner {:focus {:exclude [:integration :skip]}}
                       :setup-fn my-org.test/configure-unit-tests}}}

However, the setup-fn does not seem to be overwritten when I run poly test with:unit. Is this a bug or am I going about things incorrectly here?