Subtitles are generally way too hard for users to use. I like how Plex will offer users a selection of Subtitles with a percentage match, but even if they are right they are often out of sync. Some media players allow users to enter a +/- delay in milliseconds to sync the Subtitles to the actors voices. A better option would be a real-time dial that would allow the user to tweak the speed up and down so they will perfectly match. Ideally this value would be saved and used the next time the movie or show was watched. Thank you for considering this.
Peter Denniston