Since it also kills the userstore (the same way it kills /var/local), it effectively disables anything relying on stuff being there (so, yeah, all of my stuff ^^), but simply putting the stuff back there (using the appropriate directory from the latest source packages) after the factory reset should ensure everything will work fine after a restart
. (Provided he has a recent enough version of usbnetwork [>= 0.26.N, to be exact], one that checks/fix the test/bin folder during init, and not only install, because a factory reset will also kill the /test directory, which breaks usbnetwork).