We use on all our clusters/websites the same theme: Newspack.
Newspack is a parent-child theme. The parent theme is newspack-theme and our child theme is newspack-katharine. You need to have both in the themes folder. Always activate the child theme in WordPress.
Updates
We use Composer to download the latest version. Edit the composer.json from FDPUB Repository with the latest version for parent and child.
We never edit the themes directly!
If you need to make something theme specific, either bring this into our plugin FD Newspack Extension or create a new plugin.
Fallback theme
We use the latest “Twenty…” theme as a fallback theme.
Customizer
The Customizer must never be used – except temporarily for fast hotfixing.