When I write, I usually end up invariably creating chapters I did not intend to write when I originally wrote my outline. Usually, they are on subjects or set in places that I did not originally research or intend to include in the novel. For this, I have the glorious internet to thank. However, the internet can only go so far. Some of us do not have the Google-fu others have and so rely upon the expertise of others for our accuracy and detail.
I call today's post "piecemeal criticism" because I sometimes send these chapters to friends or colleagues with whom I have formed friendships over the years to fact check my work and give suggestions as to how I can improve my authenticity. I also do the same when I have difficult passages that need a second or third set of eyes. My friends are usually good about getting back to me rather quickly. If you are a writer worth your salt (and you want to ground your text in any modicum of reality) you will do yourself much good by surrounding yourself with these types of experts.
Even though the final deadline for my current WIP is December 21st, I am under the gun to finish the rough draft by December 8th so that I can go through the necessary editing and critique before I prepare the final text. I send whole chapters or paragraphs to others for critique all the time without giving them the entire book to read.
As a NaNoWriMo contestant, this could be a valuable way to get immediate criticism for sections of your novel that you feel need a second or third set of eyes without the critic reading the entire text and using up valuable time getting back to you.
It's worth a try.