First off why is it a issue if it shrinks?
Just remove the waste and no one will ever know they shrunk.
Usually a little shrinkage makes it easier to weed. I have notice slight shrinkage with just about every combination of vinyl and or laminate. Usually weather plays a big roll. Liner has very little adhesion to the vinyl itself so when you cut it, it is going to shrink. Full bleeds especially black (which more than likely is layers of all colors not just black ink) are going to shrink slightly. If cut properly just pull up all extra vinyl leaving only the stickers and then separate. Keep in mind that it will stop shrinking, it's not going to just keep shrinking. And if you have 2mm of gap half of that is coming from the vinyl on the outside of the cut, IE the decal is only shrinking half of that. That does sound like a awful lot of movement though. Go to the 3164G and a corresponding lam and this will not be nearly as bad.
Remember as George Costanza knows, if it is cold it will shrink.