This is something I think about all the time. As someone who has been present for almost every live stream and Q&A - I often also have the feeling of ‘I know we covered this’ and yet I’m not exactly sure where that information is stored. As the archive grows I think a more complicated indexing system will be necessary - or perhaps a reorganization of the structure of the archive.
I subscribe to some other online learning platforms myself that have a similar structure to Mirai Live and I find myself taking notes while watching the videos, with the name of the video - and scrubbing through the content when I need to refer back.
I hope that live stream resource index I have been building will assuage this issue in the interim- Live Stream Topic / Species Index