I submitted a similar issue to WebTorrent.
From your README I read that 'createReadStream' is not working as expected. Actually it will hang the program so it must be replaced.
I found that webtorrent-cli playing with mpv supports dynamic seeking by time. Serving media to localhost via WebTorrent (which is how webtorrent-cli communicates with various players) also supports ffprobe and ffmpeg seeking, though it might raise exceptions because of corruption.
I think this is because of the way ReadStream implements so it would be blocking. Switching to server seems to be the only solution.