Seeing all staged changes (or any other revision-compare) in a single editor/window

[ELLIOTTCABLE]

At the moment, I still lean on a terminal pane with git diff --cached to get an 'overview' of all the changes I'm about to commit, and double-check I didn't forget anything / include anything I didn't mean to.

In such a deeply integrated IDE, it feels so out-of-place in my workflow.

I'd love to see a GitLens feature to open a single, scrollable editor (or possibly 'notebook' editor?) containing each diff from each file that's about to be committed. Does this already exist and I just haven't noticed it? (The same interface would work well for comparing two arbitrary commits quickly.)