I think you are right. I think he used the line filter features to drill down to specific parts of a book he was working on. It sounds very cool, but I wouldn

I think you are right. I think he used the line filter features to drill down to specific parts of a book he was working on. It sounds very cool, but I wouldn't want to be bound to a mainly abandoned text editor if I were one of the most celebrated non-fiction writers. Although maybe it is his secret sauce?