The new Dynamics 365 Sitemap editor is a good addition to the platform capability to be independently providing UI editor for sitemap.
However, in most cases, we tend to use an existing sitemap as a template and remove/add the component as required.
The current experience with the Sitemap Editor is to start everything from scratch, which might lead to: Error (due to missing things of the OOTB configuration) and more time consumed to configure the sitemap and get it right.