I wouldn't really call it a modification, but a total re-rigging... I don't know of any minor modification that keeps the bait from ripping. The only thing I've figured out is running a piece of tubing through the bait where the wire is, and then either tying directly to a split ring with the treble attached, on the underside of the bait, or rigging a similar wire device, much like the existing one, only narrower, and run that through the tubing. This should allow the bait to slide up the line as soon as the treble pulls out of the bait, but I haven't tested it yet.
-Brian