We recommend using Breakdance without a theme.
Breakdance can design your entire site – headers, footers, pages, custom post types, archives, 404 pages, and more.
By default, Breakdance will disable the WordPress theme system entirely. This gives you maximum design flexibility. It also eliminates all theme bloat and gives you optimal performance.
You can change this later from from the WP admin at Breakdance > Settings > Theme. If you wish to use Breakdance with a theme, choose the Keep Theme option on this screen.
When Disable Theme is chosen, the active theme will never be loaded and has no impact on your site’s performance or appearance. When you visit the Appearance > Themes page in the WP admin, your themes will be greyed out and you’ll see a message saying your theme is successfully disabled.
If you are a developer and want the benefits of using the Disable Theme option but still need to override plugin PHP templates using a child theme, you can choose the Keep Theme option and use Breakdance Zero Theme.