I use it from time to time. Often I test manually instead of automatic, and it often works very well.
But if you want a story about an unconventional use of git bisect, I think there's one about the time I had a directory with lots of files, and one of those files was causing some problem, but I didn't know which one it was. Those files were not under version control, but I created a repo with them, where each file was added in a separate commit. Then I could use git bisect to find which file was causing the problems.
One way to implement Rust-based "plugins" is to turn the whole application/plugins relation on its head: Publish the main application as a crate, which lets the user build their own executable that uses the main application as a library. That way they can customize the app however they like, if the main app just has hooks for it.