I haven't run into this, but considered a variant on it by connecting Yousician to Beeminder -- self-binding for piano practice (
https://blog.beeminder.com/akrasia/). I encountered a couple things that made it not worthwhile for me:
- I enjoy practicing, so the benefit from self-binding is reduced.
- Yousician doesn't have a supported API, just unofficial libraries written by users, so my connection would be brittle.
- I could probably only have tracked minutes per day or week, and while that's not bad, it's not a great measure of actual progress (and over half of my practice minutes are not using Yousician).
If Yousician had an API and Beeminder had native support for it, I'd probably have linked them and made a commitment. Somewhere in here, there's something I'd use :-) I think the best element of what you described is that it's completely passive yet works for anything. If I have to do a lot of session setup (like telling it which bars I'm playing), or run it on a computer instead of a phone/tablet, I don't think the benefit would be worth the effort.
For me, I'd accept whatever tradeoffs were required in order to make it completely passive (other than starting and stopping the app for a practice session). Even if that meant I only got heuristics and had to trust its inferences, that beats taking my hands off the keyboard to mess with it. For example, maybe it estimates my tempo accuracy based on how much my recording changes when quantized, and infers that more than X seconds of silence is the start of a new analysis period (new playthrough).
Feel free to contact me if you want a sounding board.