The extensions for log, reflog, and branch are simple enough they can be implemented using custom extensions. This will make git-state far more streamlined. Easing testing and maintainability.

$ git config git-state.extensions.log "git log --oneline -10"
$ git config git-state.extensions.branches "git branch -vv"
$ git config git-state.extensions.reflog "git reflog -10"
$ git config git-state.extensions.stashes "git stash list --oneline"

Stashes is the only exception but I'm not sure the "show only default branch" feature was ever going to be useful.