I don't think that this could work. Unless I'm mistaken, signals are asynchronous, as opposed to /commands which are synchronous. When a script is running and you call a command (other than /signal) the exectution of the script stops until that specific command is finished. However, when you use signals, the script sends out a "start" message to the onSIGNAL event handlers, and the original script continues executing to its end. So by the time the signal is able to return its value, the calling script has already completed (or continued executing long past the signal call).

If I'm wrong about this, someone plz correct me.

-genius_at_work