I'm looking for a way to link to another page of my Backdrop site but to display only the main part of the page.

There are Colorbox load and Colorbox inline: Colorbox load links open forms and paths in a modal window, and Colorbox inline links open inline content (a part of a page) via an ID selector in a modal. Unfortunately the 'inline' links work only when you link to content on the same page.

In Drupal 7, I'd use https://www.drupal.org//project/colorbox_node. Does it make sense to integrate it (or parts of it) into the Backdrop Colorbox module?