It sounds like you're already on the right track. Frankly, if I wasn't trying to get out words, I'd have stalled out days ago to better plot this thing (and to have less paragraphs about stuff like the pros and cons of different anti aliasing techniques for rendering text), but to keep up my pace, I've got to go with the version of the story that's in front of me, not stop to try and find the idealized version of it that isn't.
My first NaNo in 2016 only had a few rough spots, plotting wise. The third act (of five). I had to toss out a chapter and a half and change tracks (I know you're not supposed to do that with NaNo, but it was soooo not working). My second in 2017 around October 20th, I had a spark of inspiration that answered all my questions, and by November 1st I had all the twists and turns plotted out and ready to go.
This year I have not been so lucky, and it's been a different experience. However, I think I get too obsessed with the 'perfect' plot, and when projects get away from me it takes me years to start a new one. NaNo isn't letting that happen. I've got to keep going. Maybe it won't be the best thing I wrote, but it'll be finished and I can move on to something else if I don't think this draft is worth revisiting. Maybe I'm underselling the idea. My two readers seem very intrigued and into what I've got so far. But either way, so long as I finish it, that's the main thing for me. Early next year I plan on taking that 2017 draft and working it up for self publishing (I took last year off to work up the 2016 draft and self published it earlier this year). Next NaNo? I plan on revisiting a concept I got 100,000 plus words deep into before it got away from me made me afraid to start something new for years.
Because I think NaNo forces me to keep moving forwards. Maybe it won't be the perfect plot structure. Maybe it won't have the most elegant ending. But this years idea is worth exploring, and that shelved concept is worth another go at, even if it means mostly starting over.
Let B follow A and C follow B and don't worry too much about how you get to Z. Your characters will nudge you in directions. Don't second guess it on a NaNo. Keep going. My first act is close to its crescendo. My problematic second act outline is filling up with day to day stuff, character stuff that's just shaken out of exploring the people and situations I set up, and I think I've got enough plot intrigue to soldier on.
