Thing is, no matter what regimen you’re on, there isn’t one single, fixed dose-per-day. What a lot of us do is just have our endo prescribe based on the max you might need. For instance, my Fiasp prescription is for 100u/day, which is (shh, don’t tell CVS Caremark) a ridiculous amount. But y’know, it could happen. But since mostly doesn’t, I build up a surplus, and when it gets to a certain point (e.g., my wife complains there’s no room left for actual veggies in the crisper drawer) I just hold off refilling the scrip for a bit, thus maintaining a couple months’ worth for the day the zombies attack (and trust me, they will).
I think you can do the same thing with pens, at least for your fast-acting insulin. Basal dosing is more predictable, but if you’re on good terms with your prescriber they may be willing to work with you. It’s not like you’re trying to cheat anyone, it’s that you’re trying to stay alive, and a certain safety margin is a reasonable part of doing that. Not to mention that if we weren’t targets for massive, blatant price-gouging (let alone zombies and medication-stealing robots!) none of this would be an issue at all. If someone’s cheating in this deal, it sure as hell isn’t us.