I’ve seen the SumTree pattern show up a bunch recently. As I understand it, VSCode has something similar for syntax highlighting. And I’ve both seen and written several implementations of this pattern in the various text CRDTs I’ve interacted with. - though in each case the structure is given a different name. (Eg RangeTree, ContentTree, G-Tree, etc).

It’s nice to see the idea is catching on. It’s a good one.