The opposite side of the coin is, don't get your licence signed too early. I'm two months into the second year of my two-year block and already have fulfilled the requirements for a sign-off. One examiner was happy to do the honours straight away but another pointed out that I'd only get two years from the date of signature unless I waited until within three months before the renewal date. In that case I'd have two years from the original expiry. This wasn't clear to me from a cursory glance at LASORS, and could have been an annoying faux pas on my part!