Doubt: Rendering of embedded subtitles while streaming a video

I have a React and NodeJS based webapp that is used to stream torrents that contain .mkv files.

Can this be used to render embedded subtitles of a .mkv file while it is being streamed i.e. the file has not completely downloaded ?
I know VLC Media Player can do this but I was wondering if the same thing can be achieved using ffmpegwasm in a browser or nodejs based backend where torrent streaming is handled.