I can copy a sandbox from my desktop to my laptop and use the program there when I'm going on a trip then remove it when I get home without leaving behind registry entries to nowhere. I can do this now by copying the section of the sandboxie.ini but that is a pain. If each sandbox had a self contained ini just for its settings, they would transport easily.

A sandbox named "Acme" would have a line in sandboxie.ini that gives the path and filename to the Acme sandbox, like:
FileRootPath_Acme=C:\Sandbox\%USER%\%SANDBOX%\Acme\Acme.ini. The Acme.ini file would have all the info that is in the sandboxie.ini now under [Acme].