About the Signal protocol: It’s end-to-end encrypted. It would not allow for the server to give you a customized feed. Also messages expire but I’m not sure if that’s to the protocol.

OBS to display a static image or looping video and your audio player of choice going through a playlist? Doesn’t need to be more complicated than that

I like it, as long as the absolute date is still visible when you hover over.

I can’t explain the unselectable property, but displaying relative time is considered good UX.