Hello,
It often happens to many of us to open Cubase just to try some idea, plugin, or do operations that we don’t need to keep the project and its folder.
Normally Cubase creates empty folders that remain there even after closing the unsaved project, in this way the default folder used by Cubase is unnecessarily filled by empty folders.
By disabling the default folder option, Cubase asks to locate a folder at the beginning of the creation of a new project, which I am not interested in doing for the reasons explained at the beginning.
I request that Cubase can automatically delete the created folder once closed an unsaved project.
I hope this request is shared and supported by other users and taken into consideration by the Steinberg Team.
…In the meantime, if anyone has other ideas to solve the need, let me know 
thanks