Regarding idiosyncrasies. The very first visit for an extension is a learning curve in how a particular IO want the documents presented. For example, some IO's may allow two passport page copies, and two house photos on a single A4 sheet. Others (like mine) only allow 1 passport page copy, and 1 10x5 house photo per A4 page. Some IO's are fine with just 4 photo's, other request 6. (Mine accepts 4 and scorns at a photo in the bedroom). Same with the House book, you can fit a copy of the address page, a copy of the house holders page and their ID card on 1 A4 copy, whilst mine insists they are all on a separate A4 . If in doubt, first time, make a single copy per A4 sheet. My regional office is also KK.
