saby:

A library is not a location. It's just a list of "things". In your 1st screenshot if you right-click a folder and select "open file loaction", what do you have ?

The same File Path (Location), Saby.

It's academic, anyway.  My Hidden Folder Deletion Tut, goes back to XP, that didn't have a Hidden Program Data Folder, which was introduced with Vista (Which I didn't have).

XP had Location; My Documents Folder, Vista/W7; Documents (Libraries, if you like, introduced with Vista).

File/Delete STX Files  doesn't delete all of them. The remainder are in the Hidden Render Folder. Plus copies of all source material used in a Project, by Project. Includes Video, Images, Background Music , Voice-overs etc. You wouldn't notice the build-up with a large OS (C:) Drive. You would with a small. 54GB is the record so-far. That user with XP was in danger of being unable to Defragment his HDD & would have had to Reformat it, Losing all Data.

The advice given with XP & smaller HDDs, was always to Delete Aux Files & then Hidden Render Folder, before each Edit..

I can't remember if you ever had Studio Legacy & were a Liquid User, bur Legacy Users were constantly complaining that File/Delete Aux Files didn't automatically delete all of them. Pinnacle never fixed it. Undeleted Aux Files from previous Projects, habitually screwed-up Editing & Rendering in subsequent Projects. Aux (Helper Files) were introduced with S10's new Project File Format. Previous Versions didn't have them.