If you send to everyone in your book then it will be the active ones who will see and respond first regardless. There are lots of players who are willing to take on new neighbours for answering requests. Add your name to the
ADD ME forum as well. It's helpful for when your game is at one of these goals to force close it and leave it closed for a couple of hours (if and where possible). See what you can do to get active neighbours as there is still chapter 9 which requires 20 responses and we all know that they can impact players finishing as it will spill over to the last day, so extra planning is needed. Good luck!