I made a free subtitle plugin. It comes with direction indicators for sounds, user settings, splitscreen support, support for colour coding, it’s highly customisable, and it’s controlled by a subsystem, reducing dependencies to a minimum.
I plan to add tools for authoring subtitles as time goes on if the demand exists. I am also unhappy with the state of the default UI but I’m still unfamiliar with slate, so I’ll work on that some time in the future as well.
There are still some bugs to iron out, but you shouldn’t run into them I think. Feel free to leave feedback here. Also, contributions would be more than welcome!