What I really want is a way to sync back changes made in the inspector to my css-in-js code. Does Chrome offer hooks that a library could use to accomplish this?
If you're referring to the Chrome devtools inspector - unfortunately, that's a no. To start with, no such hooks are available. Additionally, the truly hard bit is figuring out what code the resulting HTML maps to, especially when there's lists, conditional content, and nested components involved.
Eh, I don't think that's necessarily the truly hard bit, at least for common cases with a library design that works. With something like `useStyles()` from material-ui, you get a fairly unique className, and coupled with a build tool that injects the file/line/col location into the className, should be able to map directly back.