It almost looks like the purpose of this is for there to exist a single system-wide app that is used to define hotkeys - is that the case?
I can't seem to find any information on that, so who knows. It certainly implies something when it states "a unique application-specific identifier".
Maybe we can use the appname, rather than apptitle? (I think that's the first entry of appargs? Which could get us around AppTitle change issues.
You are right in saying it might be hard to track gadget titles for paths during runtime. Perhaps we can hang onto the initial value and use that forever.
I wonder if the path even is a proper path, or is just there as some "help" to indicate a unique string. Perhaps one can get away with generating unique ids...