I've actually just been creating step by step markdown docs with screenshots with this approach but I love your idea of embedding annotations in videos with JS popups and a proxy cursor. Assuming playwright allows for it, I will experiment with this.

My experience has been that customers are usually just happy to get docs that are guaranteed up to date even if they're not very good. They seem receptive to the idea of writing YAML that generates this stuff too.

I think I might blow some minds if I combine this with your popups and maybe some AI generated voiceovers.