I would love a movable, keyable camera for pencil testing motions in better context. Not just as storyboards intend with panning or zooming. But also for things like various intensities of impact camera shake and handheld shaky cam.
And if I just want to use Animation Paper to make a quick cute animation with a pan, it would be great if I didn’t have to export the frames and import it into a compositor just to get panning.
Clip Studio Paint added this a couple of updates ago and I LOVED it. The way they implemented it too is a bit interesting allowed pretty good flexibility, but UI-wise had some quirks.