When animating more complex characters with a lot of sub-layers and you plan to do bone animation and then even some more detailed vector animation, it can get confusing pretty quickly.
Sometimes i don't remember what layers i already animated and have to look through the whole thing to find them again. So a relatively easy (?) fix could be, if there was a button to just select ALL layers that have keyframes on them. That way they'll all automatically show up on the timeline. Maybe there is something like this already but if not, if any talented scripters are looking for a project, there's your idea

Thanks!