Apply the Post Content classes to the Editor Root #69491

What problem does this address?

In FSE Templates, we are allowed to add custom classes to the Post Content block. However, the same classes are not applied on the .is-root-container.wp-block-post-content in the Block Editor.

Having these classes show up would help with styling different templates within the Editor. For example, the default block gap might change for a template that is more Cover block and Columns rather than one that is more a news article with Headlines and Paragraphs.

What is your proposed solution?

Have the custom classes assigned in the Post Content block of a template be applied in Block Editor.