The reason why we in some cases ship every 80 days (instead of every 90 days) is to compensate for shipping delays. We are shipping from a centralized warehouse to all European Union countries and we have experienced that sometimes postal companies do take up to 2 weeks for delivery (even shipping to the UK sometimes takes longer than it should due to ineffective loops in the postal systems). Also, we believe it does make sense to accrue some backup capsules/supplies over time in order to compensate for such shipping delays when they happen.
However, we can skip a quarterly shipping/billing cycle at any stage if need be, i.e. once you have accrued enough backup supplies (to feel comfortable with skipping a whole quarterly billing/shipping cycle) just let us know.