Objects animated to hide/un-hide are a huge hassle since their keyframes disappear in animation editors once the object is hidden.
(this could go in the paper-cuts section, but I think its scope is too big)
One would think to enable Display Hidden in the Dope Sheet or Graph Editor to view the keyframes, but this does not work because hidden objects also become deselected
Sure, one could disable Only Selected, but that clutters the editor with other objects’ keyframes.
The keyframes are impossible to view in the Timeline since the two above options don’t even exist for it.
Getting around the problem by animating only the Render Visibility, but not the Viewport Visibility, is impracticable since the animation cannot be properly previewed.
Make all animation editors display what is selected in the outliner, rather than the viewport.
Objects stay selected in the outliner even when they are hidden
This change would be less noticeable with the upcoming synced selection for the outliner. When someone runs into this problem, they could simply disable the sync.