Board Thread:Support Requests - Getting Technical/@comment-4361443-20140518040103/@comment-452-20140518125330

Since __NOCATEGORYGALLERY__  exists, then that means it must be allowed to individually add it to each page, which means that there should be no issue with asking staff to simply disable the CategoryGalleries extension completely.

So, use Special:Contact and be sure to mention that you could just add __NOCATEGORYGALLERY__ to all category pages, but that you're asking for CategoryGalleries to be completely disabled to save time.