Huh. So it's not just plain failing, it's throwing false positives for only DW pages.

Try this one, it's testing for a different (and possibly more? Or less? accurate) classname:

javascript:void%20function(){function%20post(){var%20t=%22https://www.dreamwidth.org/update.bml%3Fevent=%22,n=window.location.href,o=e(),r=n.substr(0,n.indexOf(%22.%22));r=r.substr(r.lastIndexOf(%22/%22)+1);var%20c=document.title;c=c.substr(c.lastIndexOf(%22%20|%20%22)+3);var%20i=%22%3Cp%3E%22;i=i+'%3Cuser%20name=%22'+r+'%22%3E%20posted:%20',i=i+'%3Cstrong%3E%3Ca%20href=%22'+n+'%22%3E'+c+%22%3C/a%3E%3C/strong%3E%22,i=i,o.length%3E0%26%26(i=i+%22\n%3Cblockquote%3E%20%22+o+%22%3C/blockquote%3E%22),i+=%22%3C/p%3E%22;var%20d=%22Signal%20Boost:%20%22+c;t=t+encodeURIComponent(i)+%22%26subject=%22+encodeURIComponent(d),window.location=t}function%20e(){var%20e=%22%22;return%20window.getSelection%3Fe=window.getSelection().toString():document.selection%26%26%22Control%22!=document.selection.type%26%26(e=document.selection.createRange().text),e}var%20isMobileVersion=document.getElementsByClassName(%22security-protected%22);if(0==isMobileVersion.length)post();else{var%20check=confirm(%22Post%20is%20access-locked.%20Continue%3F%22);1==check%26%26post()}}();

...if that doesn't work, we may need somebody who actually knows what they're doing.