[branchless]

This is the main prize. Using emacs + magit I can rebase and look at per commit files whilst having a buffer open to re-order commits.

In fact magit could probably do some of this with a hook on reordering commits which would not require more git metadata.

I'm not sure I care about any of this though as if I do rebase, reorder and then hit a conflict I can't resolve I can always abort the rebase.