A while ago someone was asking for better privacy for each users Sandboxie and I understand there's no way to put the sandbox folder under your user account without running into problems so I think I have a reasonable compromise, how about an option to setup a master password for each SB sub-folder?
This way you could still maintain a certain level of privacy and no need to worry about file path issues.
And my apologies I couldn't remember the name of the original post so I left a new.