[aldanor]

It’s possible via ediff if you need it; magit devs didn’t want to implement it within magit itself IIUC because it’s fragile and changes in a temporary buffer may be lost, or something like that.

If you don’t like using ediff and really need to edit tons of hunks before staging, you could always commit/stash your dirty copy, revert back, edit files, check them in the way you want, possibly in multiple commits, then rebase your previously staged working copy on a new head and soft reset the head (it’s easier than it sounds) - which is the way I would do it in the terminal too if there was a lot to edit since it’s more fail-proof.