You know, you have a good point. I was thinking of a specific issue I had encountered, which indeed included insurance at the time.

If you are able to fill early, or to fill all refills at the same time, the prescription expiry date would be meaningless provided the script was filled prior to the 6 month deadline. I think this is up to the pharmacists discretion?

I would not try to habitually fill early with any drug that has abuse potential for fear of throwing up flags -though that is a separate matter from law.