This is similar to Ted Nelson's Xanadu in some ways, and also similarly liquid text. Nice work. The problem you're solving is a hard one. Memex maybe, one day.
In 10's there was a lot of innovation with GUIs, incl. 3d interfaces (pre virtual reality era). File managers, document environments, really interesting stuff. Tons of demos, mockups, POCs. Even YT was full of these. All of this is gone and I can not dig up any of this. I still remember quite a few concrete demos. Also, lots of hardware, like touch tables. It all kind of disappeared, I dont get it where and how. (Enterprise?)
For your perusal, here's a video of Ted demonstrating Xanadu: [0] (3min18sec to jump right to the demo)
You can also browse the book he published describing the system, Literary Machines (1981) [1] -- it's a sprawling vision but I think where the parent sees overlap is in storing each text fragment as a singular entity and visualizing the links between two fragments.
> A user may also make side-by-side connections of other types. On contemplating any two pieces of text, he may make a link between them. Thereafter, when he displays either piece of text, and asks to see the links, a link-symbol is displayed, and the other attached text — if he wishes to see it.
> Naturally, making a marginal note consists of writing the note and hooking the link. The link facility gives us much more than the attachment of mere odds and ends. It permits fully non-sequential writing, or hypertext.
BTW I really like the interface of just typing and moving my cursor around, and how easy it is to pick up a block of text and move it somewhere else.
A friend of mine is also building a memex [2](1945), as mentioned in the parent. His is a fairly radical DOS interface that he's been keying his thoughts into daily since the 80s, and it's great fun watching him try to remember something [3](2013): in about 5 or 6 keystrokes skipping across the graph of all notes, he's able to find that name on the tip of his tongue, and then hop to their phone number and the date they first met, then see what else he wrote down on that day...