If you have the keyframe always at the seek time, would that be enough? Because you said the delay is too long? If yes, would it be possible to render, for eve

If you have the keyframe always at the seek time, would that be enough? Because you said the delay is too long? If yes, would it be possible to render, for every second (half second or whatever resolution you like) a snippet which only contains the seek time until the next keyframe and than tell the webserver 'if someone seeks to time x, take this snippet and when done, jump to the original video'? You could do that transparent with some fuse fs.