If it is deep enough and wide enough, could you just drill out the bush in the drop out to form a counterbore for the cable ferrule to locate into. Obviously do not go all the way through, just enough to locate the ferrule securely. 3mm would be enough.
You can't get simpler than that.
If you do try this make sure you put a tube or something over your drill bit to stop it drawing itself right through. And use a good quality, brand new drill bit.