The stashed diff view is really nice, but it's missing untracked files in a stash (i.e., if one had stashed untracked files using git stash -u).
It is possible to see them via the git CLI, as they're the 3rd parent of the stash commit - i.e., git show stash@{0}^3 will show them). It would be great if SM showed them too, by default together with tracked file changes of the stash commit.