Most likely I am the last one to stumble across little piece of pizzazz. Since I am excited about it I thought I'd share :)
There is a simple process for adding chapters to your posted YouTube videos. In the "Description" section, after you write brief description of your video. It will look something like this:
00:00 - intro and rules
10:51 - round 1
15:72 - round 2
24:36 - round 3
I added chapters to my #Marvel Champions: The Card Game run through with Elijah https://www.youtube.com/watch?v=OyC2ZsaiG9Y&t=1328s using each turn as a marker point. Very helpful on long videos for getting an idea or where you would like to skip to in the video.