Otherwise, when used with BATCH defined so as to not be bothered by config screen and all, it will almost silently reverse obsolete patches and make you wonder why something is now broken.
Another fix is to keep PATCH_DEBUG like it is, and introduce a PATCH_VERBOSE that is like PATCH_DEBUG but with the --forward.
I went on a hunt, and PATCH_DEBUG has not had --forward since its inception. (Without any reason about why it has not.)