(Though I'm not sure how the internal database structure works with that, I think you can't save the whole text along with a deck instead of individual notes―but maybe addons can change that.)
I just thought that it might be of interest for people already using Anki and curious about incremental reading.
Now incremental reading for me is a multi-monitor and multipass approach. One monitor has Anki, the other has the thing I'm reading. I keep on reading and keep noting down questions.
I've also come to realise that the context is totally different when I frame a question during reading, and when I revisit the same question later. A lot of times I have to clean-up the question: perhaps add a little more context, change wording etc. so it becomes a bit easier to answer.