[cryptonector]

> Video is of course not necessary, just sufficient.

It should be so, but that means writing different materials, one for the actual presentation, and one for everyone who couldn't be there. It would be better to have the video.

Mind you, for accessibility and general user-friendliness, you want both. But audio/video is a great help because there will be things that the off-line materials miss.

> It would be preferable if more presentation media had a “front of card/back of card”

Yes. PowerPoint and the like generally have a public / presenter distinction, but we want three distinctions: online / off-line / presenter.