An idea of a linting rule: when an alias is used for a namespace, issue a warning when full namespace name is used to reference it:

(ns a
  (:require [clojure.walk :as w]))

(clojure.walk/walk identity identity {}) ; Issue warning here to use alias instead of a full name.

Is there a way to enable all optional linters? It also looks like the list of optional linters in https://github.com/clj-kondo/clj-kondo/blob/master/doc/config.md#enable-optional-linters is not up to date with the full list as it doesn’t mention aliased-namespace-symbol linter mentioned in a thread above.