This is a really good article that covers lots of things I keep in mind while researching for fic writing myself. I especially like your points about holding space while reading about history, and filling in the gaps when you get there. I find that this kind of learning opens you up to excitement when you spot something in a source that you've just learned about elsewhere, and it can be really motivating! (It doesn't just have to be non-fiction reading, either: Legend of the Condor Heroes planted an interest about Song and Yuan history in me that has been accreting more facts and material around it ever since.)