Develop small and Build big
If your Project will create hundreds or thousands of pages, Blueprints will display a maximun of 100 entries. This keeps your browser from bogging down with huge page counts.
You can comment out Path items to keep your Blueprints small enough to see Source files, Urls, and Vars are working as you expect without having to page through a large Blueprint.
When ready to actually Build your Project, a single mouse click can remove all commented Paths.