"Local history" is a very popular feature in the JetBrains IDEs (just search HN comments), and I remember similar tools appearing on HN several times in the past (for example https://news.ycombinator.com/item?id=29784238), so clearly there is demand for such functionality (or at least was in the past, when almost all code edits were manual).

Well, some kind of transparency would be good indeed. Open source doesn't mean open contribution.