Long story short, I imported my Zenbook Pro Duo from the states to save some money. It turns out I can't buy the warranty extension package, and that EU and US insurances don't overlap after talking to Asus support. I bought my Asus extended insurance from another store, but I can't apply it to my laptop. Sadly I can't ask for a refund either.
If anyone has a clever solution to this situation then I would be very grateful. If not, I would perhaps be able to find someone else to buy my insurance at a discounted price. However because I don't know how legal that is, I'm asking here first.