Very nice!
It would be cool if this also worked in menus, but I suppose those don’t really have much going on normally.
You can find-and-replace Graphics._onTick with SceneManager.update to make this work also in MV. (I usually write @target MV MZ at the top for cross-version plugins, even though the “MV” doesn’t really do anything.)
One suggestion I have is to also show an “other” for any unaccounted time (in/out-of scene), and to make it more clear which timings are (usually) contained inside which others.