There is nothing to fix for the rubber stoppers, and we have no plan to change the actual stoppers we are using to produce oils, if you use normal IM syringes those pieces can never go through your syringe and you can't inject it.
The oil is sterile, and filtered, so when it happens that some pieces of rubber stopper fall either because you use a big needle, or because of time, those pieces remain sterile and cannot go through the syringes unless you are using horse's ones.
There is 2400 pages over the past 2-3 years in this thread and no one got an infection or lost an ass cheek using our oils, so take it easy, I myself use our oils and it was never been an issue for me. If you are worried, you can do like the ones who are extra careful and refilter, or simply brew your own, but I believe it's unecessary.