Your demo video looks really great. I hope no one uses 0 seconds. That's one thing I find annoying about a lot of YouTube channels. They talk very fast and edit out all the spaces. My brain just simply can't keep up with it. It's too bad because the content is interesting but it's completely unintelligible and exhausting. I watch most of my videos via Chromecast, but Chromecast doesn't allow you to play videos at slower speeds. And it wouldn't add back the spaces anyway.

What if your tool was available in real time for people who wanted it and then I could have normal videos.