If it is of interest, I wrote the below to visualize the compilation queue. It appears when something is enqueued for compilation, and disappears when the queue is empty.

(when (native-comp-available-p)
  (defvar my:comp--async-running-func)
  (if (version< emacs-version "30")
      (progn
        (declare-function comp--async-runnings nil)
        (require 'comp)
        (setq my:comp--async-running-func #'comp-async-runnings))
    (require 'comp-run)
    (setq my:comp--async-running-func #'comp--async-runnings))
  (defun my/native-comp-mode-line-lighter ()
    "mode-line lighter for `my/native-comp-mode-line-mode'."
    (when comp-files-queue
      (propertize
       (format " [◴%s:%d/%d]" comp-native-version-dir (length comp-files-queue) (funcall my:comp--async-running-func))
       'face (list :height 0.75))))

  (define-minor-mode my/native-comp-mode-line-mode
    "Display the native compilation queue depth during compiles."
    :global t
    :group 'mode-line
    :lighter (:eval (my/native-comp-mode-line-lighter)))
  (when my:mode-line-native-comp
    (my/native-comp-mode-line-mode)))