You don't have to scan for new content on opening. If you want a new directory, go to Edit/Preferences/Directories and click on *Add  *then navigate to your new directory, click ok then Apply and Accept. Close DAZ Studio, reopen it and your new directory will be listed.

If you want to add a new folder, create your folder, open DAZ Studio and it will be there.

Unless I'm completely missing what you're talking about.......

Coldrake