Do you have a public example of an open source project that you are using that showcases those features?

In your opinion, is jj losing steam? How do you feel about it requiring a CLA to contribute to, which would enable the developers to go closed-source and keep all the contributions of the community? Are you afraid of vendor lock-in?

> a public example of an open source project that you are using that showcases those features?

IMO that's almost fundamentally impossible. The whole point is that it makes maintaining a "clean" linear commit history easier than git, so by the time you push anything the observable differences are already gone. At best you just see a repo without any WIP-style commits, which can be done using more effort and git alone.