Someone said section 23 was good, but I was parked against a wall for section 23 so idk if sections are different for some people, but the best section for me was 30 right after getting the energy boost ugrade. It was about dusk in the thumbnail, there's a large stretch right off the bat and you travel through the night. Should see some jellyfish. This stretch netted me about 2-2.5k and I was able to boost 3 times per before running out of fuel. GL.
EDIT: Yes, you can reload the same section over and over. If you look on the stat tracker and it doesn't show progress on your second reload simply load any other chapter, then reload 30 and run it again.