i believe `jj fix` is your -x equivalent, though im not familiar enough with it to comment on how similar the semantics actually are
jj does this for performance reasons. They don't want to perform a full checkout for every rebase action. This is simply something I disagree with
It's true that `jj fix` can be faster by not touching the working copy, but we also want a `jj run` command for the linter feature (https://github.com/jj-vcs/jj/issues/1869). It's just not done yet.