Is this a reasonable idea?

;; Defines a hiccup generating function. Adds :is-hiccup = true to response map.
(defmacro defhiccup [name body]
  (let [request (gensym)]
    `(defn ~name [~request]
       (-> ~request
        (assoc :is-hiccup true)
        (assoc :body ~body)))))

;; If response map has :is-hiccup = true, convert body hiccup into html string.
(defn wrap-hiccup-body->html [handler]
  (fn [request]
    (let [response (handler request)
          body (:body response)
          response (if (:is-hiccup response)
                     (assoc response :body (str (hiccup/html body)))
                     response)]
      response)))

;; For reitit
(def hiccup->html-middleware
  {:name ::hiccup->html
   :description "Convert hiccup responses to html"
   :wrap wrap-hiccup-body->html})

(comment 
  
  (defhiccup hi-fragment
    [:div "Hi"])
  
  (hi-fragment {}) ;;=> {:is-hiccup true, :body [:div "Hi"]} 
  
  ,,)