To throw my hat into this, I like the idea of having some storyboarding tools in the engine.
In particular, if it would be possible to add a robust timeline tool, ala Aeon Timeline (doesn’t need to be that detailed) that would be awesome.
Very few tools let you define custom calendars or multi-year time span timelines, and you often need just that very thing for games. It would also be consistent with the other types of storyboarding tools mentioned here (articy:draft’s ones).