Is it possible to use Gutenberg or Elementor to add content to Listing pages? For example, I would like to add some content using Gutenberg blocks to https://domainname.com/listing/example-of-listing/ . Right now it looks like only Visual editor is available to edit Listing and Vendor pages.
Yes, it’s possible to override any HivePress layout using the block editor (Gutenberg) in HivePress/Templates section (please note that this feature is still in Beta). Here’s an example of overriding the Listings page Overview | HivePress Templates - YouTube
If you don’t want to override the whole page, it’s also possible to insert custom content using code snippets Search · user:hivepress hivepress/v1/templates · GitHub or widget areas in the Appearance/Widgets section.