IMPORTANT - My customer has just managed to delete all the work that I did using Breakdance, because I told them to edit the 'Slim SEO' meta tag boxes which are only shown on the Gutenberg edit page. For some reason, despite my instructions with screenshots, they managed to click the DANGEROUS "Use default editor" link and then save. This deleted all of the Breakdance page meta JSON data and even a WordPress restore of a revision would not work. If there a magic trick to recover a Breakdance page after someone has save it as Gutenberg, PLEASE tell us. In the meantime, I have restored the web site to last night's backup, but all of today's work has gone. Lesson learned and hopefully you guys will remove this HORRIBLE link button!