       (fstar-subp-enqueue-until next-start)
     (user-error "Cannot find a full block to process")))
 
-(defun fstar-sub-overlay-contains-build-config (overlay)
-  "Check if OVERLAY contains a build-config header."
-  (save-excursion
-    (save-match-data
-      (goto-char (overlay-start overlay))
-      (cl-loop while (re-search-forward (regexp-quote fstar-build-config-header) (overlay-end overlay) t)
-               thereis (fstar-in-build-config-p)))))
-
 (defun fstar-subp-pop-overlay (overlay)
   "Remove overlay OVERLAY and issue the corresponding #pop command."
   (fstar-assert (fstar-subp-available-p))
-  (if (fstar-sub-overlay-contains-build-config overlay)
-      (fstar-subp-kill)
-    (fstar-subp--query fstar-subp--cancel nil))
+  (fstar-subp--query fstar-subp--cancel nil)
   (delete-overlay overlay))
 
 (defun fstar-subp-retract-one (overlay)

           (save-excursion
             (goto-char comment-start-pos)
             (cond
              ((looking-at (regexp-quote fstar-build-config-header)) font-lock-doc-face)
              ((looking-at (regexp-quote "(*** ")) '(:inherit font-lock-doc-face :height 2.5))
              ((looking-at (regexp-quote "(**+ ")) '(:inherit font-lock-doc-face :height 1.8))
              ((looking-at (regexp-quote "(**! ")) '(:inherit font-lock-doc-face :height 1.5))

      (fstar-find-fun-and-args
       (1 'font-lock-keyword-face)
       (fstar-find-id (fstar-subexpr-pre-matcher 1) nil (1 'font-lock-variable-name-face)))
      (,fstar-syntax-ambiguous
       (0 'fstar-ambiguous-face append))
      ("!"
