Idea:
Show capes in Replay Cinema
More information:
I wear the Minecon 2013 cape on my skin, and every time I use replay, it doesn’t show my cape. I’d be better if it showed your cape in replay cinema. 
I looked at the discord to see why capes are disabled in replays and it seems like they are disabled for optimization purposes. So although it would be nice to have them in replays, I don’t think they’ll be added in unfortunately.