I wanted a way to tweak the width of post titles to optimize where it breaks to a new line.
I created the metabox with Advanced Custom Fields using the Range field type. I set the maximum value and default value to the current max-width of the post title, and the minimum to something reasonable.
I then customized my theme to add the max-width CSS if the value is less than 1168px. Since my site is built on Genesis, I leveraged the Markup API by adding this to
You also need to make sure your Gutenberg editor styles match the frontend of your site. See my post on Building a Gutenberg website for details.