> frequently have me touch a few different unrelated bits simultaneously (eg editing foo, but fix a typo in bar) which I use stage to iteratively commit. From the jj stuff I have read thus far, my workflow would be a bit clunky to adapt.

I do this too! I find it easier in jj than in git. I wrote out a lengthy thing about the "oh I found a typo" use case here: https://lobste.rs/s/yjqd6d/against_names#c_7yfw7g

`jj split --interactive` is built in, and will handle that exact case for you. It also comes with a built in TUI so you can select lines right from the terminal immediately.

You can even do `jj split --parallel` which will not only split the changes into two commits, but then make the commits siblings (instead of child/parent), so you can immediately push things if they're easy fixes.

I have a base of B with my commit @ that contains a bunch of changes.

    B --> @

`jj split` will give me this graph, where `X` contains the changes I selected, and `@` contains all the changes I didn't select:

    B --> X --> @

Instead, if I did `jj split --parallel`, I would get this:

    B --> @
     \
      --> X

Let's say `X` is a typofix and @ contains your feature you're not done with yet. OK, just run `jj git push -c X` and jj will create a branch name for you, and push it to the remote for code review. Done. You don't have to switch branches or do anything. You basically can just stop thinking about X since it will probably get merged.