Now if only someone would invent a tool to do the opposite. I have too easy a time of forgetting what I wrote, and penning new lines in obliviousness. It's a habit from many years of stream-of-consciousness writing a la The Artist's Way and https://750words.com.
The hard thing, I find, is structuring text so that each paragraph has a purpose in relation to the others. I was once taught this in school, but I haven't kept up with my practice.
So, maybe a tool that takes previous paragraphs and--contrariwise to letting them recede into obscurity--shoves them repeatedly in my face?
Anyway, very elegant and pleasant. Like a foggy quayside cafe.
Is this for non-fiction/business writing?
If so, I recommend looking at Barbara Minto's Pyramid Principle.
https://www.amazon.com/Pyramid-Principle-Logic-Writing-Think...
Haha, I'm actually working on that too! Currently experimenting with a graph based editor.
Also, you might like The Fieldstone Method (Weinberg).
PS. Andy Matuschak's notes: http://notes.andymatuschak.org have some good tips on a similar subject. (My "digital garden" is more of a choose your own adventure book, I'm not married to a single methodology, but I appreciate much of their work)