i am going to take a guess that maybe you are not locked out, especially if the item is under pharmacy benefits. Here is why. Suppose you went on a a medication for something. Lets say stinky feet. Now that medication works for a few months but your docotr says hey those shoes still smell. So here is another medication we can try.
Would your pharmacy benefit manger say oh no, you must take the first medicament for 3 years? I dont think so.
If you wish to test this out, call omnipod, or tandem or medtronic and ask for insurance verification. They will test what your options are. Hardware and pharmacy rarely mix, but the pod is different. remember these companies want to sell their devices so they will be delighted to call your insurance.
My guess is you have the world open to you for making a choice.