[_ck_]

fel64: No, there’s been hooks for the post form for as long as I can remember.

Unfortunately that’s only for new posts. For editing existing posts there is absolutely no way to affect the template without editing it. There’s no hooks for edit_form() or any of it’s sub-functions or the template loader (the loader does the include AFTER the hook so nothing can be placed afterwards. I requested some hooks many month ago but they may have been missed (or ignored). This plugin will require (one, simple) edit of the edit-post.php template.

(In theory it could be done via the bb_get_footer but that’s really messy and the footer hook is AFTER the footer has been rendered).