A standard MVC widget in Sitfinity 9.2 will have the following two options within "single item settings"...
* Auto-generated page
* Selected existing page...
If I am outputting listing items that do not need to have a detail view at all, then I tend to just leave "Auto-generated page" selected as there is no existing page to select.
The problem with this is that it becomes possible to navigate to the generated detail version of each item in the listing for example by navigating to something like: www.foowebsite.com/listing-page/listing-item-title
This page will look visually broken as there will be no styling for the detail view.
I know I can hide these URLs from the sitemap in Admin > Settings > Adv > Sitemap > Exclude Types.
But hiding from the sitemap isn't really solving the issue. The URLs should go to 404.