A recursive option for secured folders should be available for advanced users.
This should be implemented as single on/off option, meaning that all directory-related options should be or not be recursive, including future support for selecting folders when encrypting/decrypting.
A list of forbidden folders must be enforced for all directory-related options including secured folders, such as C:\, C:\Windows, C:\Program Files, C:\Program Files (x86), C:\Users - also ensuring that localized versions of these folder names are covered if required. (There is already partial support for this, verify if this is sufficient, and also if takes localization into account).
Default is "off", to enable it a warning text and entering the password will be required.
The warning should state something similar to "You are about to enable a dangerous option. If you are not careful, you may affect more data then you intend causing operations to take very long time, or breaking other softwares including the operating system. Are you sure?".