Not yet.
Tento skript by neměl být instalován přímo. Jedná se o knihovnu, kterou by měly jiné skripty využívat pomocí meta příkazu // @require https://update.greasyfork.org/scripts/2599/184155/GM%202%20port%20-%20Function%20Override%20Helper.js
GreasyMonkey 2.x Beta will break lots scripts, this library has made to help function hooking.
It provides 2.x API exportFunction and cloneInto for 1.x support (Which is just dummy sandbox).
It's well documented in source how to use each functions.
This library is backward compatible.