TYPO3 Core

Given the following RTE configuration:

editor:
  config:
    heading:
      options:
        - { model: 'paragraph', title: 'Paragraph' }
        - { model: 'heading2', view: 'h2', title: 'Heading 2', class: 'h2' }
        - { model: 'heading3', view: 'h3', title: 'Heading 3', class: 'h3' }
        - { model: 'heading4', view: 'h4', title: 'Heading 4', class: 'h4' }

I would expect that when selecting a heading (e.g. "heading2") the defined class (e.g. "h2") is attached to the HTML alement. But this is not the case (neither in RTE directly nor in frontend).

According to the CKeditor documentation this should be done like in the example above:
https://ckeditor.com/docs/ckeditor5/latest/features/headings.html#configuring-toolbar-buttons