It is possible for a free account user to categorize his forms into subfolder?

Currently, only the admin can create subfolders and categorize their forms. But when an admin share a folder with its subfolders to a user, that user cannot categorize their created forms into subfolders. Their forms only appear in the parent folder.

The forms that are shared with the "sub-user" will appear in the "Shared folder", if those forms are categorized into folders, that will be shown in the sub-users end, and he can sort them by folder:

Now, regarding to the forms that belong to the account that is added under yours as "sub-user", they can categorize their own forms in folders too.

It is important to note that the sub-user feature is just to share access to your forms with someone else's account, not to inherit account benefits, so the ability to categorize their forms will depend on the account type they have(free, Bronze, Silver, or Gold).