I find it really annoying looking up videos and not immediately knowing what I'm clicking on because the thumbnails are often pitch black which ofc gives zero info. It's often due to videos often having fade-in intros or a simple mistake the first frame isn't rendered so it's pitch black.
So I want request a different thumbnail system. In the case where a thumbnail is pitch black or near black, or is just a bad thumbnail in general, moderators (or users with special perms) should be able to change the thumbnail to an image of a different timestamp so that it's more representative of the video. Would make for a much better overall experience on the site imo. Well, it could be argued that if implemented, it'd be fine to even let all users be able to change thumbnails.
I think black thumbnails really punish the artists as well and may deter people from clicking the videos or rewatching them as it's confusing to find out which is which when so many have black thumbnails. A lot of artists' livelihoods depend on earnings from animations and the inability to customize thumbnails harms their views and the attention their art might get.
Another suggestion I have is the ability to enable labels with titles for videos. Just a simple label underneath with the title of the animation, can be turned on or off in settings.
I don't know anything about the technical side of things and how feasible it would be to implement these features. Take these just as complaints/ideas.